256621836 has 12 divisors (see below), whose sum is σ = 598784312. Its totient is φ = 85540608.

The previous prime is 256621831. The next prime is 256621867. The reversal of 256621836 is 638126652.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 256621794 and 256621803.

It is not an unprimeable number, because it can be changed into a prime (256621831) 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, 10692565 + ... + 10692588.

Almost surely, 2^256621836 is an apocalyptic number.

It is an amenable number.

256621836 is an abundant number, since it is smaller than the sum of its proper divisors (342162476).

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

256621836 is a wasteful number, since it uses less digits than its factorization.

256621836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21385160 (or 21385158 counting only the distinct ones).

The product of its digits is 103680, while the sum is 39.

The square root of 256621836 is about 16019.4205887729. The cubic root of 256621836 is about 635.4741212859.

The spelling of 256621836 in words is "two hundred fifty-six million, six hundred twenty-one thousand, eight hundred thirty-six".