256447392137 has 4 divisors (see below), whose sum is σ = 256448573460. Its totient is φ = 256446210816.

The previous prime is 256447392127. The next prime is 256447392169. The reversal of 256447392137 is 731293744652.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 172039130176 + 84408261961 = 414776^2 + 290531^2 .

It is a cyclic number.

It is not a de Polignac number, because 256447392137 - 2⁸ = 256447391881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256447392107) 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, 160712 + ... + 733977.

It is an arithmetic number, because the mean of its divisors is an integer number (64112143365).

Almost surely, 2^256447392137 is an apocalyptic number.

It is an amenable number.

256447392137 is a deficient number, since it is larger than the sum of its proper divisors (1181323).

256447392137 is an equidigital number, since it uses as much as digits as its factorization.

256447392137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1181322.

The product of its digits is 7620480, while the sum is 53.

The spelling of 256447392137 in words is "two hundred fifty-six billion, four hundred forty-seven million, three hundred ninety-two thousand, one hundred thirty-seven".