12561831 has 32 divisors (see below), whose sum is σ = 20044800. Its totient is φ = 7750080.

The previous prime is 12561823. The next prime is 12561859. The reversal of 12561831 is 13816521.

12561831 is a `hidden beast` number, since 12 + 5 + 618 + 31 = 666.

It is not a de Polignac number, because 12561831 - 2³ = 12561823 is a prime.

It is a super-2 number, since 2×12561831² = 315599196145122, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 12561795 and 12561804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23851 + ... + 24371.

It is an arithmetic number, because the mean of its divisors is an integer number (626400).

Almost surely, 2^12561831 is an apocalyptic number.

12561831 is a deficient number, since it is larger than the sum of its proper divisors (7482969).

12561831 is a wasteful number, since it uses less digits than its factorization.

12561831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596 (or 590 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 12561831 is about 3544.2673431896. The cubic root of 12561831 is about 232.4614712430.

The spelling of 12561831 in words is "twelve million, five hundred sixty-one thousand, eight hundred thirty-one".