257215171 has 4 divisors (see below), whose sum is σ = 259092792. Its totient is φ = 255337552.

The previous prime is 257215169. The next prime is 257215177. The reversal of 257215171 is 171512752.

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

It is a cyclic number.

It is not a de Polignac number, because 257215171 - 2¹ = 257215169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257215177) 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, 938605 + ... + 938878.

It is an arithmetic number, because the mean of its divisors is an integer number (64773198).

Almost surely, 2^257215171 is an apocalyptic number.

257215171 is a deficient number, since it is larger than the sum of its proper divisors (1877621).

257215171 is a wasteful number, since it uses less digits than its factorization.

257215171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1877620.

The product of its digits is 4900, while the sum is 31.

The square root of 257215171 is about 16037.9291368930. The cubic root of 257215171 is about 635.9635039314.

The spelling of 257215171 in words is "two hundred fifty-seven million, two hundred fifteen thousand, one hundred seventy-one".