12531591 has 20 divisors (see below), whose sum is σ = 18878904. Its totient is φ = 8283600.

The previous prime is 12531569. The next prime is 12531593. The reversal of 12531591 is 19513521.

It is not a de Polignac number, because 12531591 - 2¹⁵ = 12498823 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12531593) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10021 + ... + 11201.

Almost surely, 2^12531591 is an apocalyptic number.

12531591 is a deficient number, since it is larger than the sum of its proper divisors (6347313).

12531591 is a wasteful number, since it uses less digits than its factorization.

12531591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324 (or 1315 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 12531591 is about 3539.9987288133. The cubic root of 12531591 is about 232.2747871192.

The spelling of 12531591 in words is "twelve million, five hundred thirty-one thousand, five hundred ninety-one".