213718257 has 24 divisors (see below), whose sum is σ = 323473696. Its totient is φ = 140994432.

The previous prime is 213718249. The next prime is 213718261. The reversal of 213718257 is 752817312.

It is not a de Polignac number, because 213718257 - 2³ = 213718249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213718157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19038 + ... + 28104.

Almost surely, 2^213718257 is an apocalyptic number.

213718257 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

213718257 is a deficient number, since it is larger than the sum of its proper divisors (109755439).

213718257 is an frugal number, since it uses more digits than its factorization.

213718257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9179 (or 9167 counting only the distinct ones).

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

The square root of 213718257 is about 14619.1058892122. The cubic root of 213718257 is about 597.8797916861.

The spelling of 213718257 in words is "two hundred thirteen million, seven hundred eighteen thousand, two hundred fifty-seven".