256703560639 has 2 divisors, whose sum is σ = 256703560640. Its totient is φ = 256703560638.

The previous prime is 256703560591. The next prime is 256703560657. The reversal of 256703560639 is 936065307652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256703560639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256703560339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128351780319 + 128351780320.

It is an arithmetic number, because the mean of its divisors is an integer number (128351780320).

Almost surely, 2^256703560639 is an apocalyptic number.

256703560639 is a deficient number, since it is larger than the sum of its proper divisors (1).

256703560639 is an equidigital number, since it uses as much as digits as its factorization.

256703560639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6123600, while the sum is 52.

The spelling of 256703560639 in words is "two hundred fifty-six billion, seven hundred three million, five hundred sixty thousand, six hundred thirty-nine".