257213505 has 32 divisors (see below), whose sum is σ = 421303680. Its totient is φ = 133952000.

The previous prime is 257213497. The next prime is 257213543. The reversal of 257213505 is 505312752.

It is not a de Polignac number, because 257213505 - 2³ = 257213497 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 198901 + ... + 200189.

It is an arithmetic number, because the mean of its divisors is an integer number (13165740).

Almost surely, 2^257213505 is an apocalyptic number.

It is an amenable number.

257213505 is a deficient number, since it is larger than the sum of its proper divisors (164090175).

257213505 is a wasteful number, since it uses less digits than its factorization.

257213505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1601.

The product of its (nonzero) digits is 10500, while the sum is 30.

The square root of 257213505 is about 16037.8771974348. The cubic root of 257213505 is about 635.9621308689.

The spelling of 257213505 in words is "two hundred fifty-seven million, two hundred thirteen thousand, five hundred five".