2556632661 has 8 divisors (see below), whose sum is σ = 3718738464. Its totient is φ = 1549474320.

The previous prime is 2556632627. The next prime is 2556632693. The reversal of 2556632661 is 1662366552.

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

It is not a de Polignac number, because 2556632661 - 2⁹ = 2556632149 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556636661) 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, 38736826 + ... + 38736891.

It is an arithmetic number, because the mean of its divisors is an integer number (464842308).

Almost surely, 2^2556632661 is an apocalyptic number.

It is an amenable number.

2556632661 is a deficient number, since it is larger than the sum of its proper divisors (1162105803).

2556632661 is a wasteful number, since it uses less digits than its factorization.

2556632661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77473731.

The product of its digits is 388800, while the sum is 42.

The square root of 2556632661 is about 50563.1551725167. The cubic root of 2556632661 is about 1367.3806953415.

The spelling of 2556632661 in words is "two billion, five hundred fifty-six million, six hundred thirty-two thousand, six hundred sixty-one".