12561338879 has 8 divisors (see below), whose sum is σ = 13624638048. Its totient is φ = 11534083840.

The previous prime is 12561338821. The next prime is 12561338903. The reversal of 12561338879 is 97883316521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-12561338879 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12561338879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561638879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9010307 + ... + 9011700.

It is an arithmetic number, because the mean of its divisors is an integer number (1703079756).

Almost surely, 2^12561338879 is an apocalyptic number.

12561338879 is a deficient number, since it is larger than the sum of its proper divisors (1063299169).

12561338879 is a wasteful number, since it uses less digits than its factorization.

12561338879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18022065.

The product of its digits is 2177280, while the sum is 53.

The spelling of 12561338879 in words is "twelve billion, five hundred sixty-one million, three hundred thirty-eight thousand, eight hundred seventy-nine".