12561939 has 24 divisors (see below), whose sum is σ = 20159280. Its totient is φ = 7727616.

The previous prime is 12561931. The next prime is 12561947. The reversal of 12561939 is 93916521.

12561939 = 977² + 978² + ... + 989².

12561939 is a `hidden beast` number, since 1 + 2 + 5 + 619 + 39 = 666.

It is an interprime number because it is at equal distance from previous prime (12561931) and next prime (12561947).

It is not a de Polignac number, because 12561939 - 2³ = 12561931 is a prime.

It is a super-2 number, since 2×12561939² = 315604622879442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12561931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3187 + ... + 5939.

It is an arithmetic number, because the mean of its divisors is an integer number (839970).

Almost surely, 2^12561939 is an apocalyptic number.

12561939 is a deficient number, since it is larger than the sum of its proper divisors (7597341).

12561939 is a wasteful number, since it uses less digits than its factorization.

12561939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2788 (or 2769 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 12561939 is about 3544.2825790278. The cubic root of 12561939 is about 232.4621374348.

The spelling of 12561939 in words is "twelve million, five hundred sixty-one thousand, nine hundred thirty-nine".