213311531 has 2 divisors, whose sum is σ = 213311532. Its totient is φ = 213311530.

The previous prime is 213311489. The next prime is 213311627. The reversal of 213311531 is 135113312.

213311531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213311531 is a prime.

It is a super-2 number, since 2×213311531² = 91003618515127922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (213311731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106655765 + 106655766.

It is an arithmetic number, because the mean of its divisors is an integer number (106655766).

Almost surely, 2^213311531 is an apocalyptic number.

213311531 is a deficient number, since it is larger than the sum of its proper divisors (1).

213311531 is an equidigital number, since it uses as much as digits as its factorization.

213311531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 270, while the sum is 20.

The square root of 213311531 is about 14605.1884958736. The cubic root of 213311531 is about 597.5002769558.

Adding to 213311531 its reverse (135113312), we get a palindrome (348424843).

The spelling of 213311531 in words is "two hundred thirteen million, three hundred eleven thousand, five hundred thirty-one".