213131217 has 16 divisors (see below), whose sum is σ = 306936000. Its totient is φ = 130771392.

The previous prime is 213131209. The next prime is 213131249. The reversal of 213131217 is 712131312.

It is a happy number.

It is not a de Polignac number, because 213131217 - 2³ = 213131209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 213131193 and 213131202.

It is not an unprimeable number, because it can be changed into a prime (213131207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5659 + ... + 21407.

It is an arithmetic number, because the mean of its divisors is an integer number (19183500).

Almost surely, 2^213131217 is an apocalyptic number.

It is an amenable number.

213131217 is a deficient number, since it is larger than the sum of its proper divisors (93804783).

213131217 is a wasteful number, since it uses less digits than its factorization.

213131217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16112.

The product of its digits is 252, while the sum is 21.

The square root of 213131217 is about 14599.0142475442. The cubic root of 213131217 is about 597.3318721883.

Adding to 213131217 its reverse (712131312), we get a palindrome (925262529).

The spelling of 213131217 in words is "two hundred thirteen million, one hundred thirty-one thousand, two hundred seventeen".