12556861 has 4 divisors (see below), whose sum is σ = 12579424. Its totient is φ = 12534300.

The previous prime is 12556811. The next prime is 12556867. The reversal of 12556861 is 16865521.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16865521 = 19 ⋅887659.

It is a cyclic number.

It is not a de Polignac number, because 12556861 - 2¹⁷ = 12425789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12556867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10425 + ... + 11566.

It is an arithmetic number, because the mean of its divisors is an integer number (3144856).

Almost surely, 2^12556861 is an apocalyptic number.

It is an amenable number.

12556861 is a deficient number, since it is larger than the sum of its proper divisors (22563).

12556861 is an equidigital number, since it uses as much as digits as its factorization.

12556861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22562.

The product of its digits is 14400, while the sum is 34.

The square root of 12556861 is about 3543.5661416150. The cubic root of 12556861 is about 232.4308099508.

The spelling of 12556861 in words is "twelve million, five hundred fifty-six thousand, eight hundred sixty-one".