257405243 has 2 divisors, whose sum is σ = 257405244. Its totient is φ = 257405242.

The previous prime is 257405237. The next prime is 257405341. The reversal of 257405243 is 342504752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257405243 - 2¹⁰ = 257404219 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (257404243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128702621 + 128702622.

It is an arithmetic number, because the mean of its divisors is an integer number (128702622).

Almost surely, 2^257405243 is an apocalyptic number.

257405243 is a deficient number, since it is larger than the sum of its proper divisors (1).

257405243 is an equidigital number, since it uses as much as digits as its factorization.

257405243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 33600, while the sum is 32.

The square root of 257405243 is about 16043.8537452820. The cubic root of 257405243 is about 636.1201161197.

Adding to 257405243 its reverse (342504752), we get a palindrome (599909995).

The spelling of 257405243 in words is "two hundred fifty-seven million, four hundred five thousand, two hundred forty-three".