31312013 has 4 divisors (see below), whose sum is σ = 31551168.
Its totient is φ = 31072860.
The previous prime is 31312007. The next prime is 31312033. The reversal of 31312013 is 31021313.
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 a cyclic number.
It is not a de Polignac number, because 31312013 - 24 = 31311997 is a prime.
It is a super-2 number, since 2×313120132 = 1960884316224338, which contains 22 as substring.
It is a Duffinian number.
It is a Curzon number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (31312033) 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, 119381 + ... + 119642.
It is an arithmetic number, because the mean of its divisors is an integer number (7887792).
Almost surely, 231312013 is an apocalyptic number.
It is an amenable number.
31312013 is a deficient number, since it is larger than the sum of its proper divisors (239155).
31312013 is a wasteful number, since it uses less digits than its factorization.
31312013 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 239154.
The product of its (nonzero) digits is 54, while the sum is 14.
The square root of 31312013 is about 5595.7138061198.
The cubic root of 31312013 is about 315.1884754315.
Adding to 31312013 its reverse (31021313), we get a palindrome (62333326).
The spelling of 31312013 in words is "thirty-one million, three hundred twelve thousand, thirteen".