2556557609679 has 8 divisors (see below), whose sum is σ = 3787492755120. Its totient is φ = 1704371739768.

The previous prime is 2556557609629. The next prime is 2556557609717. The reversal of 2556557609679 is 9769067556552.

2556557609679 is a `hidden beast` number, since 2 + 5 + 5 + 6 + 5 + 5 + 7 + 609 + 6 + 7 + 9 = 666.

It is not a de Polignac number, because 2556557609679 - 2⁸ = 2556557609423 is a prime.

It is a super-6 number, since 6×2556557609679⁶ (a number of 76 digits) contains 666666 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556557609629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47343659412 + ... + 47343659465.

It is an arithmetic number, because the mean of its divisors is an integer number (473436594390).

Almost surely, 2^{2556557609679} is an apocalyptic number.

2556557609679 is a deficient number, since it is larger than the sum of its proper divisors (1230935145441).

2556557609679 is an equidigital number, since it uses as much as digits as its factorization.

2556557609679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94687318886 (or 94687318880 counting only the distinct ones).

The product of its (nonzero) digits is 1071630000, while the sum is 72.

The spelling of 2556557609679 in words is "two trillion, five hundred fifty-six billion, five hundred fifty-seven million, six hundred nine thousand, six hundred seventy-nine".