12611531 has 4 divisors (see below), whose sum is σ = 12619200. Its totient is φ = 12603864.

The previous prime is 12611519. The next prime is 12611581. The reversal of 12611531 is 13511621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 13511621 = 1187 ⋅11383.

It is a cyclic number.

It is not a de Polignac number, because 12611531 - 2¹⁸ = 12349387 is a prime.

It is a super-2 number, since 2×12611531² = 318101428327922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12611581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251 + ... + 5028.

It is an arithmetic number, because the mean of its divisors is an integer number (3154800).

Almost surely, 2^12611531 is an apocalyptic number.

12611531 is a deficient number, since it is larger than the sum of its proper divisors (7669).

12611531 is an equidigital number, since it uses as much as digits as its factorization.

12611531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7668.

The product of its digits is 180, while the sum is 20.

The square root of 12611531 is about 3551.2717440376. The cubic root of 12611531 is about 232.7676403005.

The spelling of 12611531 in words is "twelve million, six hundred eleven thousand, five hundred thirty-one".