257715649 has 2 divisors, whose sum is σ = 257715650. Its totient is φ = 257715648.

The previous prime is 257715643. The next prime is 257715659. The reversal of 257715649 is 946517752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 222964624 + 34751025 = 14932^2 + 5895^2 .

It is a cyclic number.

It is not a de Polignac number, because 257715649 - 2⁹ = 257715137 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 257715599 and 257715608.

It is not a weakly prime, because it can be changed into another prime (257715643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128857824 + 128857825.

It is an arithmetic number, because the mean of its divisors is an integer number (128857825).

Almost surely, 2^257715649 is an apocalyptic number.

It is an amenable number.

257715649 is a deficient number, since it is larger than the sum of its proper divisors (1).

257715649 is an equidigital number, since it uses as much as digits as its factorization.

257715649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 529200, while the sum is 46.

The square root of 257715649 is about 16053.5245039835. The cubic root of 257715649 is about 636.3757133262.

The spelling of 257715649 in words is "two hundred fifty-seven million, seven hundred fifteen thousand, six hundred forty-nine".