213431345 has 24 divisors (see below), whose sum is σ = 275129784. Its totient is φ = 158394368.

The previous prime is 213431321. The next prime is 213431359. The reversal of 213431345 is 543134312.

It can be written as a sum of positive squares in 12 ways, for example, as 135303424 + 78127921 = 11632^2 + 8839^2 .

It is a de Polignac number, because none of the positive numbers 2^k-213431345 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 673127 + ... + 673443.

It is an arithmetic number, because the mean of its divisors is an integer number (11463741).

Almost surely, 2^213431345 is an apocalyptic number.

It is an amenable number.

213431345 is a deficient number, since it is larger than the sum of its proper divisors (61698439).

213431345 is an equidigital number, since it uses as much as digits as its factorization.

213431345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 428 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 213431345 is about 14609.2896815691. The cubic root of 213431345 is about 597.6121251035.

Adding to 213431345 its reverse (543134312), we get a palindrome (756565657).

The spelling of 213431345 in words is "two hundred thirteen million, four hundred thirty-one thousand, three hundred forty-five".