23131515 has 16 divisors (see below), whose sum is σ = 40375296. Its totient is φ = 11215200.

The previous prime is 23131513. The next prime is 23131517. The reversal of 23131515 is 51513132.

It is an interprime number because it is at equal distance from previous prime (23131513) and next prime (23131517).

It is not a de Polignac number, because 23131515 - 2¹ = 23131513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 23131491 and 23131500.

It is not an unprimeable number, because it can be changed into a prime (23131513) 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, 69931 + ... + 70260.

It is an arithmetic number, because the mean of its divisors is an integer number (2523456).

Almost surely, 2^23131515 is an apocalyptic number.

23131515 is a deficient number, since it is larger than the sum of its proper divisors (17243781).

23131515 is a wasteful number, since it uses less digits than its factorization.

23131515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140210.

The product of its digits is 450, while the sum is 21.

The square root of 23131515 is about 4809.5233651579. The cubic root of 23131515 is about 284.9277132766.

Adding to 23131515 its reverse (51513132), we get a palindrome (74644647).

It can be divided in two parts, 2313 and 1515, that added together give a triangular number (3828 = T₈₇).

The spelling of 23131515 in words is "twenty-three million, one hundred thirty-one thousand, five hundred fifteen".