21620510156 has 48 divisors (see below), whose sum is σ = 44902643520. Its totient is φ = 8916065280.

The previous prime is 21620510143. The next prime is 21620510239. The reversal of 21620510156 is 65101502612.

It is a happy 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 15 ways as a sum of consecutive naturals, for example, 45191 + ... + 212798.

It is an arithmetic number, because the mean of its divisors is an integer number (935471740).

Almost surely, 2^21620510156 is an apocalyptic number.

It is an amenable number.

21620510156 is an abundant number, since it is smaller than the sum of its proper divisors (23282133364).

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

21620510156 is a wasteful number, since it uses less digits than its factorization.

21620510156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258114 (or 258112 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 21620510156 in words is "twenty-one billion, six hundred twenty million, five hundred ten thousand, one hundred fifty-six".