21112705256 has 16 divisors (see below), whose sum is σ = 39603942240. Its totient is φ = 10551654000.

The previous prime is 21112705253. The next prime is 21112705283. The reversal of 21112705256 is 65250721112.

It is not an unprimeable number, because it can be changed into a prime (21112705253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 568196 + ... + 604211.

It is an arithmetic number, because the mean of its divisors is an integer number (2475246390).

Almost surely, 2^21112705256 is an apocalyptic number.

It is an amenable number.

21112705256 is a deficient number, since it is larger than the sum of its proper divisors (18491236984).

21112705256 is a wasteful number, since it uses less digits than its factorization.

21112705256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1174664 (or 1174660 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 32.

The spelling of 21112705256 in words is "twenty-one billion, one hundred twelve million, seven hundred five thousand, two hundred fifty-six".