256163513987 has 2 divisors, whose sum is σ = 256163513988. Its totient is φ = 256163513986.

The previous prime is 256163513953. The next prime is 256163514011. The reversal of 256163513987 is 789315361652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256163513987 - 2²⁰ = 256162465411 is a prime.

It is not a weakly prime, because it can be changed into another prime (256163513087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128081756993 + 128081756994.

It is an arithmetic number, because the mean of its divisors is an integer number (128081756994).

Almost surely, 2^256163513987 is an apocalyptic number.

256163513987 is a deficient number, since it is larger than the sum of its proper divisors (1).

256163513987 is an equidigital number, since it uses as much as digits as its factorization.

256163513987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8164800, while the sum is 56.

The spelling of 256163513987 in words is "two hundred fifty-six billion, one hundred sixty-three million, five hundred thirteen thousand, nine hundred eighty-seven".