31325513 has 4 divisors (see below), whose sum is σ = 31839108. Its totient is φ = 30811920.

The previous prime is 31325507. The next prime is 31325533. The reversal of 31325513 is 31552313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31552313 = 13 ⋅2427101.

It can be written as a sum of positive squares in 2 ways, for example, as 7246864 + 24078649 = 2692^2 + 4907^2 .

It is a cyclic number.

It is not a de Polignac number, because 31325513 - 2¹⁴ = 31309129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31325533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256706 + ... + 256827.

It is an arithmetic number, because the mean of its divisors is an integer number (7959777).

Almost surely, 2^31325513 is an apocalyptic number.

It is an amenable number.

31325513 is a deficient number, since it is larger than the sum of its proper divisors (513595).

31325513 is an equidigital number, since it uses as much as digits as its factorization.

31325513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513594.

The product of its digits is 1350, while the sum is 23.

The square root of 31325513 is about 5596.9199565475. The cubic root of 31325513 is about 315.2337661751.

Adding to 31325513 its reverse (31552313), we get a palindrome (62877826).

The spelling of 31325513 in words is "thirty-one million, three hundred twenty-five thousand, five hundred thirteen".