31145513 has 16 divisors (see below), whose sum is σ = 38177280. Its totient is φ = 24800256.

The previous prime is 31145509. The next prime is 31145557. The reversal of 31145513 is 31554113.

It is a cyclic number.

It is not a de Polignac number, because 31145513 - 2² = 31145509 is a prime.

It is a super-4 number, since 4×31145513⁴ (a number of 31 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31145593) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7745 + ... + 11057.

It is an arithmetic number, because the mean of its divisors is an integer number (2386080).

Almost surely, 2^31145513 is an apocalyptic number.

It is an amenable number.

31145513 is a deficient number, since it is larger than the sum of its proper divisors (7031767).

31145513 is a wasteful number, since it uses less digits than its factorization.

31145513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3416.

The product of its digits is 900, while the sum is 23.

The square root of 31145513 is about 5580.8165173207. The cubic root of 31145513 is about 314.6288161635.

Adding to 31145513 its reverse (31554113), we get a palindrome (62699626).

The spelling of 31145513 in words is "thirty-one million, one hundred forty-five thousand, five hundred thirteen".