31531412213 has 4 divisors (see below), whose sum is σ = 36035899680. Its totient is φ = 27026924748.

The previous prime is 31531412207. The next prime is 31531412219. The reversal of 31531412213 is 31221413513.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (31531412207) and next prime (31531412219).

It is a cyclic number.

It is not a de Polignac number, because 31531412213 - 2⁸ = 31531411957 is a prime.

It is a super-2 number, since 2×31531412213² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31531412219) 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, 2252243723 + ... + 2252243736.

It is an arithmetic number, because the mean of its divisors is an integer number (9008974920).

Almost surely, 2^31531412213 is an apocalyptic number.

It is an amenable number.

31531412213 is a deficient number, since it is larger than the sum of its proper divisors (4504487467).

31531412213 is an equidigital number, since it uses as much as digits as its factorization.

31531412213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504487466.

The product of its digits is 2160, while the sum is 26.

Adding to 31531412213 its reverse (31221413513), we get a palindrome (62752825726).

The spelling of 31531412213 in words is "thirty-one billion, five hundred thirty-one million, four hundred twelve thousand, two hundred thirteen".