257655649 has 2 divisors, whose sum is σ = 257655650. Its totient is φ = 257655648.

The previous prime is 257655611. The next prime is 257655659. The reversal of 257655649 is 946556752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 226653025 + 31002624 = 15055^2 + 5568^2 .

It is a cyclic number.

It is not a de Polignac number, because 257655649 - 2⁹ = 257655137 is a prime.

It is a super-2 number, since 2×257655649² = 132772866923222402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257655659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128827824 + 128827825.

It is an arithmetic number, because the mean of its divisors is an integer number (128827825).

Almost surely, 2^257655649 is an apocalyptic number.

It is an amenable number.

257655649 is a deficient number, since it is larger than the sum of its proper divisors (1).

257655649 is an equidigital number, since it uses as much as digits as its factorization.

257655649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2268000, while the sum is 49.

The square root of 257655649 is about 16051.6556466926. The cubic root of 257655649 is about 636.3263236125.

The spelling of 257655649 in words is "two hundred fifty-seven million, six hundred fifty-five thousand, six hundred forty-nine".