Search a number
-
+
21121210 = 25111571223
BaseRepresentation
bin101000010010…
…0100010111010
31110202001212001
41100210202322
520401334320
62032411214
7344345605
oct120444272
943661761
1021121210
1110a16750
1270a6b0a
1344b6876
142b3b33c
151cc320a
hex14248ba

21121210 has 32 divisors (see below), whose sum is σ = 41772672. Its totient is φ = 7625280.

The previous prime is 21121207. The next prime is 21121211. The reversal of 21121210 is 1212112.

It is a super-2 number, since 2×211212102 = 892211023728200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21121211) 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, 16659 + ... + 17881.

It is an arithmetic number, because the mean of its divisors is an integer number (1305396).

Almost surely, 221121210 is an apocalyptic number.

21121210 is a deficient number, since it is larger than the sum of its proper divisors (20651462).

21121210 is a wasteful number, since it uses less digits than its factorization.

21121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21121210 is about 4595.7817615722. The cubic root of 21121210 is about 276.4222078952.

Adding to 21121210 its reverse (1212112), we get a palindrome (22333322).

The spelling of 21121210 in words is "twenty-one million, one hundred twenty-one thousand, two hundred ten".

Divisors: 1 2 5 10 11 22 55 110 157 314 785 1223 1570 1727 2446 3454 6115 8635 12230 13453 17270 26906 67265 134530 192011 384022 960055 1920110 2112121 4224242 10560605 21121210