21112500256 has 96 divisors (see below), whose sum is σ = 44694115200. Its totient is φ = 9787852800.

The previous prime is 21112500197. The next prime is 21112500257. The reversal of 21112500256 is 65200521112.

It is a self number, because there is not a number n which added to its sum of digits gives 21112500256.

It is not an unprimeable number, because it can be changed into a prime (21112500257) 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, 5463381 + ... + 5467243.

It is an arithmetic number, because the mean of its divisors is an integer number (465563700).

Almost surely, 2^21112500256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112500256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22347057600).

21112500256 is an abundant number, since it is smaller than the sum of its proper divisors (23581614944).

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

21112500256 is a wasteful number, since it uses less digits than its factorization.

21112500256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4082 (or 4074 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

The spelling of 21112500256 in words is "twenty-one billion, one hundred twelve million, five hundred thousand, two hundred fifty-six".