31323613 has 4 divisors (see below), whose sum is σ = 31362588. Its totient is φ = 31284640.

The previous prime is 31323581. The next prime is 31323623. The reversal of 31323613 is 31632313.

31323613 = 3957² + 3958².

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 15665764 + 15657849 = 3958^2 + 3957^2 .

It is a cyclic number.

It is not a de Polignac number, because 31323613 - 2⁵ = 31323581 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 (31323623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18256 + ... + 19897.

It is an arithmetic number, because the mean of its divisors is an integer number (7840647).

Almost surely, 2^31323613 is an apocalyptic number.

31323613 is the 3958-th centered square number.

It is an amenable number.

31323613 is a deficient number, since it is larger than the sum of its proper divisors (38975).

31323613 is an equidigital number, since it uses as much as digits as its factorization.

31323613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38974.

The product of its digits is 972, while the sum is 22.

The square root of 31323613 is about 5596.7502177603. The cubic root of 31323613 is about 315.2273927092.

Adding to 31323613 its reverse (31632313), we get a palindrome (62955926).

The spelling of 31323613 in words is "thirty-one million, three hundred twenty-three thousand, six hundred thirteen".