256215161 has 2 divisors, whose sum is σ = 256215162. Its totient is φ = 256215160.

The previous prime is 256215151. The next prime is 256215163. The reversal of 256215161 is 161512652.

It is a happy number.

256215161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177715561 + 78499600 = 13331^2 + 8860^2 .

It is a cyclic number.

It is not a de Polignac number, because 256215161 - 2⁶ = 256215097 is a prime.

Together with 256215163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256215163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128107580 + 128107581.

It is an arithmetic number, because the mean of its divisors is an integer number (128107581).

Almost surely, 2^256215161 is an apocalyptic number.

It is an amenable number.

256215161 is a deficient number, since it is larger than the sum of its proper divisors (1).

256215161 is an equidigital number, since it uses as much as digits as its factorization.

256215161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 29.

The square root of 256215161 is about 16006.7223690548. The cubic root of 256215161 is about 635.1382599308.

The spelling of 256215161 in words is "two hundred fifty-six million, two hundred fifteen thousand, one hundred sixty-one".