257240407 has 2 divisors, whose sum is σ = 257240408. Its totient is φ = 257240406.

The previous prime is 257240383. The next prime is 257240453. The reversal of 257240407 is 704042752.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257240407 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257249407) 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, 128620203 + 128620204.

It is an arithmetic number, because the mean of its divisors is an integer number (128620204).

Almost surely, 2^257240407 is an apocalyptic number.

257240407 is a deficient number, since it is larger than the sum of its proper divisors (1).

257240407 is an equidigital number, since it uses as much as digits as its factorization.

257240407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15680, while the sum is 31.

The square root of 257240407 is about 16038.7158775259. The cubic root of 257240407 is about 635.9843018883.

The spelling of 257240407 in words is "two hundred fifty-seven million, two hundred forty thousand, four hundred seven".