213305531 has 4 divisors (see below), whose sum is σ = 213442200. Its totient is φ = 213168864.

The previous prime is 213305501. The next prime is 213305537. The reversal of 213305531 is 135503312.

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 213305531 - 2¹⁴ = 213289147 is a prime.

It is a super-2 number, since 2×213305531² = 90998499110383922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213305497 and 213305506.

It is not an unprimeable number, because it can be changed into a prime (213305537) 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, 65966 + ... + 69123.

It is an arithmetic number, because the mean of its divisors is an integer number (53360550).

Almost surely, 2^213305531 is an apocalyptic number.

213305531 is a deficient number, since it is larger than the sum of its proper divisors (136669).

213305531 is a wasteful number, since it uses less digits than its factorization.

213305531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136668.

The product of its (nonzero) digits is 1350, while the sum is 23.

The square root of 213305531 is about 14604.9830879738. The cubic root of 213305531 is about 597.4946747657.

Adding to 213305531 its reverse (135503312), we get a palindrome (348808843).

The spelling of 213305531 in words is "two hundred thirteen million, three hundred five thousand, five hundred thirty-one".