256723835477 has 2 divisors, whose sum is σ = 256723835478. Its totient is φ = 256723835476.

The previous prime is 256723835429. The next prime is 256723835507. The reversal of 256723835477 is 774538327652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 254364887716 + 2358947761 = 504346^2 + 48569^2 .

It is a cyclic number.

It is not a de Polignac number, because 256723835477 - 2⁶ = 256723835413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256723865477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128361917738 + 128361917739.

It is an arithmetic number, because the mean of its divisors is an integer number (128361917739).

Almost surely, 2^256723835477 is an apocalyptic number.

It is an amenable number.

256723835477 is a deficient number, since it is larger than the sum of its proper divisors (1).

256723835477 is an equidigital number, since it uses as much as digits as its factorization.

256723835477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59270400, while the sum is 59.

The spelling of 256723835477 in words is "two hundred fifty-six billion, seven hundred twenty-three million, eight hundred thirty-five thousand, four hundred seventy-seven".