256623953 has 2 divisors, whose sum is σ = 256623954. Its totient is φ = 256623952.

The previous prime is 256623943. The next prime is 256623979. The reversal of 256623953 is 359326652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 252555664 + 4068289 = 15892^2 + 2017^2 .

It is a cyclic number.

It is not a de Polignac number, because 256623953 - 2¹⁶ = 256558417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 256623953.

It is not a weakly prime, because it can be changed into another prime (256623923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128311976 + 128311977.

It is an arithmetic number, because the mean of its divisors is an integer number (128311977).

Almost surely, 2^256623953 is an apocalyptic number.

It is an amenable number.

256623953 is a deficient number, since it is larger than the sum of its proper divisors (1).

256623953 is an equidigital number, since it uses as much as digits as its factorization.

256623953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 291600, while the sum is 41.

The square root of 256623953 is about 16019.4866646844. The cubic root of 256623953 is about 635.4758687275.

The spelling of 256623953 in words is "two hundred fifty-six million, six hundred twenty-three thousand, nine hundred fifty-three".