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21100211220 = 223511263121559
BaseRepresentation
bin10011101001101010…
…111010110000010100
32000110111202210022110
4103221222322300110
5321203123224340
613405430431020
71344611556534
oct235152726024
960414683273
1021100211220
118a48578aa0
12410a502470
131cb36007aa
14104247b4c4
15837644680
hex4e9abac14

21100211220 has 96 divisors (see below), whose sum is σ = 64697149440. Its totient is φ = 5095711360.

The previous prime is 21100211219. The next prime is 21100211257. The reversal of 21100211220 is 2211200112.

It is a super-2 number, since 2×211002112202 (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21100211196 and 21100211205.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112801 + ... + 234359.

It is an arithmetic number, because the mean of its divisors is an integer number (673928640).

Almost surely, 221100211220 is an apocalyptic number.

21100211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32348574720).

21100211220 is an abundant number, since it is smaller than the sum of its proper divisors (43596938220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21100211220 is a wasteful number, since it uses less digits than its factorization.

21100211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121845 (or 121843 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21100211220 its reverse (2211200112), we get a palindrome (23311411332).

It can be divided in two parts, 211002 and 11220, that added together give a palindrome (222222).

The spelling of 21100211220 in words is "twenty-one billion, one hundred million, two hundred eleven thousand, two hundred twenty".

Divisors: 1 2 3 4 5 6 10 11 12 15 20 22 30 33 44 55 60 66 110 132 165 220 263 330 526 660 789 1052 1315 1578 2630 2893 3156 3945 5260 5786 7890 8679 11572 14465 15780 17358 28930 34716 43395 57860 86790 121559 173580 243118 364677 486236 607795 729354 1215590 1337149 1458708 1823385 2431180 2674298 3646770 4011447 5348596 6685745 7293540 8022894 13371490 16045788 20057235 26742980 31970017 40114470 63940034 80228940 95910051 127880068 159850085 191820102 319700170 351670187 383640204 479550255 639400340 703340374 959100510 1055010561 1406680748 1758350935 1918201020 2110021122 3516701870 4220042244 5275052805 7033403740 10550105610 21100211220