256642544620 has 48 divisors (see below), whose sum is σ = 671936848128. Its totient is φ = 79992480960.

The previous prime is 256642544603. The next prime is 256642544621. The reversal of 256642544620 is 26445246652.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (256642544621) 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, 83323962 + ... + 83327041.

It is an arithmetic number, because the mean of its divisors is an integer number (13998684336).

Almost surely, 2^256642544620 is an apocalyptic number.

256642544620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256642544620 is an abundant number, since it is smaller than the sum of its proper divisors (415294303508).

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

256642544620 is a wasteful number, since it uses less digits than its factorization.

256642544620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166651030 (or 166651028 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 46.

The spelling of 256642544620 in words is "two hundred fifty-six billion, six hundred forty-two million, five hundred forty-four thousand, six hundred twenty".