257781213 has 12 divisors (see below), whose sum is σ = 384362368. Its totient is φ = 166310280.

The previous prime is 257781211. The next prime is 257781299. The reversal of 257781213 is 312187752.

257781213 is a `hidden beast` number, since 2 + 577 + 81 + 2 + 1 + 3 = 666.

It is not a de Polignac number, because 257781213 - 2¹ = 257781211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257781211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461695 + ... + 462252.

Almost surely, 2^257781213 is an apocalyptic number.

It is an amenable number.

257781213 is a deficient number, since it is larger than the sum of its proper divisors (126581155).

257781213 is a wasteful number, since it uses less digits than its factorization.

257781213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923984 (or 923981 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 257781213 is about 16055.5664179125. The cubic root of 257781213 is about 636.4296743483.

The spelling of 257781213 in words is "two hundred fifty-seven million, seven hundred eighty-one thousand, two hundred thirteen".