256611899 has 2 divisors, whose sum is σ = 256611900. Its totient is φ = 256611898.

The previous prime is 256611881. The next prime is 256611911. The reversal of 256611899 is 998116652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256611899 - 2⁸ = 256611643 is a prime.

It is not a weakly prime, because it can be changed into another prime (256611499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128305949 + 128305950.

It is an arithmetic number, because the mean of its divisors is an integer number (128305950).

Almost surely, 2^256611899 is an apocalyptic number.

256611899 is a deficient number, since it is larger than the sum of its proper divisors (1).

256611899 is an equidigital number, since it uses as much as digits as its factorization.

256611899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 47.

The square root of 256611899 is about 16019.1104309821. The cubic root of 256611899 is about 635.4659188301.

The spelling of 256611899 in words is "two hundred fifty-six million, six hundred eleven thousand, eight hundred ninety-nine".