257742847 has 4 divisors (see below), whose sum is σ = 271308280. Its totient is φ = 244177416.

The previous prime is 257742833. The next prime is 257742887. The reversal of 257742847 is 748247752.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257742847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 257742797 and 257742806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257742827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6782688 + ... + 6782725.

It is an arithmetic number, because the mean of its divisors is an integer number (67827070).

Almost surely, 2^257742847 is an apocalyptic number.

257742847 is a deficient number, since it is larger than the sum of its proper divisors (13565433).

257742847 is a wasteful number, since it uses less digits than its factorization.

257742847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13565432.

The product of its digits is 878080, while the sum is 46.

The square root of 257742847 is about 16054.3715853346. The cubic root of 257742847 is about 636.3980991583.

The spelling of 257742847 in words is "two hundred fifty-seven million, seven hundred forty-two thousand, eight hundred forty-seven".