21680526252 has 48 divisors (see below), whose sum is σ = 63070624512. Its totient is φ = 5631305280.

The previous prime is 21680526107. The next prime is 21680526311. The reversal of 21680526252 is 25262508612.

It is a happy number.

It is a super-2 number, since 2×21680526252² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21680526252.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11730963 + ... + 11732810.

It is an arithmetic number, because the mean of its divisors is an integer number (1313971344).

Almost surely, 2^21680526252 is an apocalyptic number.

21680526252 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21680526252 is an abundant number, since it is smaller than the sum of its proper divisors (41390098260).

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

21680526252 is a wasteful number, since it uses less digits than its factorization.

21680526252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23463798 (or 23463796 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The spelling of 21680526252 in words is "twenty-one billion, six hundred eighty million, five hundred twenty-six thousand, two hundred fifty-two".