2556660642 has 8 divisors (see below), whose sum is σ = 5113321296. Its totient is φ = 852220212.

The previous prime is 2556660637. The next prime is 2556660671. The reversal of 2556660642 is 2460666552.

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

2556660642 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 2556660594 and 2556660603.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213055048 + ... + 213055059.

It is an arithmetic number, because the mean of its divisors is an integer number (639165162).

Almost surely, 2^2556660642 is an apocalyptic number.

2556660642 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2556660642 is a wasteful number, since it uses less digits than its factorization.

2556660642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426110112.

The product of its (nonzero) digits is 518400, while the sum is 42.

The square root of 2556660642 is about 50563.4318653313. The cubic root of 2556660642 is about 1367.3856837442.

The spelling of 2556660642 in words is "two billion, five hundred fifty-six million, six hundred sixty thousand, six hundred forty-two".