256631138532 has 36 divisors (see below), whose sum is σ = 682848937680. Its totient is φ = 81041411952.

The previous prime is 256631138531. The next prime is 256631138537. The reversal of 256631138532 is 235831136652.

256631138532 is a `hidden beast` number, since 2 + 5 + 6 + 631 + 1 + 3 + 8 + 5 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (256631138531) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 187595178 + ... + 187596545.

Almost surely, 2^256631138532 is an apocalyptic number.

It is an amenable number.

256631138532 is an abundant number, since it is smaller than the sum of its proper divisors (426217799148).

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

256631138532 is a wasteful number, since it uses less digits than its factorization.

256631138532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375191752 (or 375191747 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The spelling of 256631138532 in words is "two hundred fifty-six billion, six hundred thirty-one million, one hundred thirty-eight thousand, five hundred thirty-two".