12879865855609 has 81 divisors (see below), whose sum is σ = 14855686135533. Its totient is φ = 11162768371200.

The previous prime is 12879865855579. The next prime is 12879865855709. The reversal of 12879865855609 is 90655856897821.

The square root of 12879865855609 is 3588853.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 907380079225 + 11972485776384 = 952565^2 + 3460128^2 .

It is not a de Polignac number, because 12879865855609 - 2¹⁹ = 12879865331321 is a prime.

It is a super-3 number, since 3×12879865855609³ (a number of 40 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12879865855709) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 47527180144 + ... + 47527180414.

Almost surely, 2^{12879865855609} is an apocalyptic number.

12879865855609 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

12879865855609 is the 3588853-rd square number.

12879865855609 is the 1794427-th centered octagonal number.

It is an amenable number.

12879865855609 is a deficient number, since it is larger than the sum of its proper divisors (1975820279924).

12879865855609 is an frugal number, since it uses more digits than its factorization.

12879865855609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 2612736000, while the sum is 79.

The spelling of 12879865855609 in words is "twelve trillion, eight hundred seventy-nine billion, eight hundred sixty-five million, eight hundred fifty-five thousand, six hundred nine".