256747061 has 2 divisors, whose sum is σ = 256747062. Its totient is φ = 256747060.

The previous prime is 256747037. The next prime is 256747087. The reversal of 256747061 is 160747652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256192036 + 555025 = 16006^2 + 745^2 .

It is a cyclic number.

It is not a de Polignac number, because 256747061 - 2²² = 252552757 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256747021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128373530 + 128373531.

It is an arithmetic number, because the mean of its divisors is an integer number (128373531).

Almost surely, 2^256747061 is an apocalyptic number.

It is an amenable number.

256747061 is a deficient number, since it is larger than the sum of its proper divisors (1).

256747061 is an equidigital number, since it uses as much as digits as its factorization.

256747061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 256747061 is about 16023.3286491915. The cubic root of 256747061 is about 635.5774696054.

The spelling of 256747061 in words is "two hundred fifty-six million, seven hundred forty-seven thousand, sixty-one".