31640313 has 4 divisors (see below), whose sum is σ = 42187088. Its totient is φ = 21093540.

The previous prime is 31640309. The next prime is 31640327. The reversal of 31640313 is 31304613.

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 not a de Polignac number, because 31640313 - 2² = 31640309 is a prime.

It is a super-2 number, since 2×31640313² = 2002218813475938, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31640313.

It is not an unprimeable number, because it can be changed into a prime (31640813) 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, 5273383 + ... + 5273388.

It is an arithmetic number, because the mean of its divisors is an integer number (10546772).

Almost surely, 2^31640313 is an apocalyptic number.

It is an amenable number.

31640313 is a deficient number, since it is larger than the sum of its proper divisors (10546775).

31640313 is a wasteful number, since it uses less digits than its factorization.

31640313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10546774.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 31640313 is about 5624.9722665983. The cubic root of 31640313 is about 316.2862098759.

Adding to 31640313 its reverse (31304613), we get a palindrome (62944926).

The spelling of 31640313 in words is "thirty-one million, six hundred forty thousand, three hundred thirteen".