256631677045109 has 2 divisors, whose sum is σ = 256631677045110. Its totient is φ = 256631677045108.

The previous prime is 256631677045087. The next prime is 256631677045147. The reversal of 256631677045109 is 901540776136652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180399954003025 + 76231723042084 = 13431305^2 + 8731078^2 .

It is a cyclic number.

It is not a de Polignac number, because 256631677045109 - 2³⁶ = 256562957568373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256631677045189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128315838522554 + 128315838522555.

It is an arithmetic number, because the mean of its divisors is an integer number (128315838522555).

Almost surely, 2^{256631677045109} is an apocalyptic number.

It is an amenable number.

256631677045109 is a deficient number, since it is larger than the sum of its proper divisors (1).

256631677045109 is an equidigital number, since it uses as much as digits as its factorization.

256631677045109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 57153600, while the sum is 62.

The spelling of 256631677045109 in words is "two hundred fifty-six trillion, six hundred thirty-one billion, six hundred seventy-seven million, forty-five thousand, one hundred nine".