256611757 has 2 divisors, whose sum is σ = 256611758. Its totient is φ = 256611756.

The previous prime is 256611721. The next prime is 256611767. The reversal of 256611757 is 757116652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158482921 + 98128836 = 12589^2 + 9906^2 .

It is a cyclic number.

It is not a de Polignac number, because 256611757 - 2⁷ = 256611629 is a prime.

It is a super-3 number, since 3×256611757³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256611767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128305878 + 128305879.

It is an arithmetic number, because the mean of its divisors is an integer number (128305879).

Almost surely, 2^256611757 is an apocalyptic number.

It is an amenable number.

256611757 is a deficient number, since it is larger than the sum of its proper divisors (1).

256611757 is an equidigital number, since it uses as much as digits as its factorization.

256611757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 88200, while the sum is 40.

The square root of 256611757 is about 16019.1059987753. The cubic root of 256611757 is about 635.4658016152.

The spelling of 256611757 in words is "two hundred fifty-six million, six hundred eleven thousand, seven hundred fifty-seven".