13185531 has 8 divisors (see below), whose sum is σ = 19534160. Its totient is φ = 8790336.

The previous prime is 13185493. The next prime is 13185539. The reversal of 13185531 is 13558131.

It is not a de Polignac number, because 13185531 - 2¹⁸ = 12923387 is a prime.

It is a super-2 number, since 2×13185531² = 347716455503922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 488353 = 13185531 / (1 + 3 + 1 + 8 + 5 + 5 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13185495 and 13185504.

It is not an unprimeable number, because it can be changed into a prime (13185539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 244150 + ... + 244203.

It is an arithmetic number, because the mean of its divisors is an integer number (2441770).

Almost surely, 2^13185531 is an apocalyptic number.

13185531 is a deficient number, since it is larger than the sum of its proper divisors (6348629).

13185531 is an equidigital number, since it uses as much as digits as its factorization.

13185531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488362 (or 488356 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 13185531 is about 3631.1886483630. The cubic root of 13185531 is about 236.2467674035.

The spelling of 13185531 in words is "thirteen million, one hundred eighty-five thousand, five hundred thirty-one".