256977397 has 2 divisors, whose sum is σ = 256977398. Its totient is φ = 256977396.

The previous prime is 256977373. The next prime is 256977421. The reversal of 256977397 is 793779652.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (256977373) and next prime (256977421).

It can be written as a sum of positive squares in only one way, i.e., 168636196 + 88341201 = 12986^2 + 9399^2 .

It is a cyclic number.

It is not a de Polignac number, because 256977397 - 2⁷ = 256977269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256977317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128488698 + 128488699.

It is an arithmetic number, because the mean of its divisors is an integer number (128488699).

Almost surely, 2^256977397 is an apocalyptic number.

It is an amenable number.

256977397 is a deficient number, since it is larger than the sum of its proper divisors (1).

256977397 is an equidigital number, since it uses as much as digits as its factorization.

256977397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5000940, while the sum is 55.

The square root of 256977397 is about 16030.5145581793. The cubic root of 256977397 is about 635.7674784210.

The spelling of 256977397 in words is "two hundred fifty-six million, nine hundred seventy-seven thousand, three hundred ninety-seven".