256436651 has 2 divisors, whose sum is σ = 256436652. Its totient is φ = 256436650.

The previous prime is 256436639. The next prime is 256436657. The reversal of 256436651 is 156634652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256436651 - 2¹⁸ = 256174507 is a prime.

It is not a weakly prime, because it can be changed into another prime (256436657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128218325 + 128218326.

It is an arithmetic number, because the mean of its divisors is an integer number (128218326).

Almost surely, 2^256436651 is an apocalyptic number.

256436651 is a deficient number, since it is larger than the sum of its proper divisors (1).

256436651 is an equidigital number, since it uses as much as digits as its factorization.

256436651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 38.

The square root of 256436651 is about 16013.6395301006. The cubic root of 256436651 is about 635.3212262772.

The spelling of 256436651 in words is "two hundred fifty-six million, four hundred thirty-six thousand, six hundred fifty-one".