256979492849 has 2 divisors, whose sum is σ = 256979492850. Its totient is φ = 256979492848.

The previous prime is 256979492837. The next prime is 256979492879. The reversal of 256979492849 is 948294979652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 234311179249 + 22668313600 = 484057^2 + 150560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256979492849 is a prime.

It is not a weakly prime, because it can be changed into another prime (256979492879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128489746424 + 128489746425.

It is an arithmetic number, because the mean of its divisors is an integer number (128489746425).

Almost surely, 2^256979492849 is an apocalyptic number.

It is an amenable number.

256979492849 is a deficient number, since it is larger than the sum of its proper divisors (1).

256979492849 is an equidigital number, since it uses as much as digits as its factorization.

256979492849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705438720, while the sum is 74.

The spelling of 256979492849 in words is "two hundred fifty-six billion, nine hundred seventy-nine million, four hundred ninety-two thousand, eight hundred forty-nine".