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21188832680 = 2351954750969
BaseRepresentation
bin10011101110111100…
…111110110110101000
32000200200112020002202
4103232330332312220
5321343320121210
613422314115332
71350036051251
oct235674766650
960620466082
1021188832680
118a935a8674
12413411bb48
131cc8a8c122
141050149b28
158402ec9a5
hex4eef3eda8

21188832680 has 64 divisors (see below), whose sum is σ = 50276808000. Its totient is φ = 8014616064.

The previous prime is 21188832653. The next prime is 21188832689. The reversal of 21188832680 is 8623888112.

It is not an unprimeable number, because it can be changed into a prime (21188832689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 390236 + ... + 441204.

It is an arithmetic number, because the mean of its divisors is an integer number (785575125).

Almost surely, 221188832680 is an apocalyptic number.

21188832680 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 21188832680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25138404000).

21188832680 is an abundant number, since it is smaller than the sum of its proper divisors (29087975320).

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

21188832680 is a wasteful number, since it uses less digits than its factorization.

21188832680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51546 (or 51542 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 47.

The spelling of 21188832680 in words is "twenty-one billion, one hundred eighty-eight million, eight hundred thirty-two thousand, six hundred eighty".

Divisors: 1 2 4 5 8 10 19 20 38 40 76 95 152 190 380 547 760 1094 2188 2735 4376 5470 10393 10940 20786 21880 41572 50969 51965 83144 101938 103930 203876 207860 254845 407752 415720 509690 968411 1019380 1936822 2038760 3873644 4842055 7747288 9684110 19368220 27880043 38736440 55760086 111520172 139400215 223040344 278800430 529720817 557600860 1059441634 1115201720 2118883268 2648604085 4237766536 5297208170 10594416340 21188832680