256257961 has 2 divisors, whose sum is σ = 256257962. Its totient is φ = 256257960.

The previous prime is 256257943. The next prime is 256257979. The reversal of 256257961 is 169752652.

It is a balanced prime because it is at equal distance from previous prime (256257943) and next prime (256257979).

It can be written as a sum of positive squares in only one way, i.e., 145082025 + 111175936 = 12045^2 + 10544^2 .

It is a cyclic number.

It is not a de Polignac number, because 256257961 - 2⁵ = 256257929 is a prime.

It is not a weakly prime, because it can be changed into another prime (256257931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128128980 + 128128981.

It is an arithmetic number, because the mean of its divisors is an integer number (128128981).

Almost surely, 2^256257961 is an apocalyptic number.

It is an amenable number.

256257961 is a deficient number, since it is larger than the sum of its proper divisors (1).

256257961 is an equidigital number, since it uses as much as digits as its factorization.

256257961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226800, while the sum is 43.

The square root of 256257961 is about 16008.0592515145. The cubic root of 256257961 is about 635.1736239635.

The spelling of 256257961 in words is "two hundred fifty-six million, two hundred fifty-seven thousand, nine hundred sixty-one".