31331413 has 4 divisors (see below), whose sum is σ = 31364460. Its totient is φ = 31298368.

The previous prime is 31331407. The next prime is 31331429. The reversal of 31331413 is 31413313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27804529 + 3526884 = 5273^2 + 1878^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31331413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31335413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15058 + ... + 17011.

It is an arithmetic number, because the mean of its divisors is an integer number (7841115).

Almost surely, 2^31331413 is an apocalyptic number.

It is an amenable number.

31331413 is a deficient number, since it is larger than the sum of its proper divisors (33047).

31331413 is an equidigital number, since it uses as much as digits as its factorization.

31331413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33046.

The product of its digits is 324, while the sum is 19.

The square root of 31331413 is about 5597.4470073418. The cubic root of 31331413 is about 315.2535558214.

Adding to 31331413 its reverse (31413313), we get a palindrome (62744726).

The spelling of 31331413 in words is "thirty-one million, three hundred thirty-one thousand, four hundred thirteen".