12561861 has 16 divisors (see below), whose sum is σ = 19099584. Its totient is φ = 7275264.

The previous prime is 12561859. The next prime is 12561863. The reversal of 12561861 is 16816521.

It is an interprime number because it is at equal distance from previous prime (12561859) and next prime (12561863).

It is not a de Polignac number, because 12561861 - 2¹ = 12561859 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8811 + ... + 10136.

It is an arithmetic number, because the mean of its divisors is an integer number (1193724).

Almost surely, 2^12561861 is an apocalyptic number.

It is an amenable number.

12561861 is a deficient number, since it is larger than the sum of its proper divisors (6537723).

12561861 is a wasteful number, since it uses less digits than its factorization.

12561861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18980.

The product of its digits is 2880, while the sum is 30.

The square root of 12561861 is about 3544.2715753734. The cubic root of 12561861 is about 232.4616562967.

The spelling of 12561861 in words is "twelve million, five hundred sixty-one thousand, eight hundred sixty-one".