2556231661 has 8 divisors (see below), whose sum is σ = 2667879360. Its totient is φ = 2444626272.

The previous prime is 2556231641. The next prime is 2556231679. The reversal of 2556231661 is 1661326552.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2556231661 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 2556231661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556231611) 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, 221121 + ... + 232393.

It is an arithmetic number, because the mean of its divisors is an integer number (333484920).

Almost surely, 2^2556231661 is an apocalyptic number.

It is an amenable number.

2556231661 is a deficient number, since it is larger than the sum of its proper divisors (111647699).

2556231661 is a wasteful number, since it uses less digits than its factorization.

2556231661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21155.

The product of its digits is 64800, while the sum is 37.

The square root of 2556231661 is about 50559.1896790287. The cubic root of 2556231661 is about 1367.3092017793.

The spelling of 2556231661 in words is "two billion, five hundred fifty-six million, two hundred thirty-one thousand, six hundred sixty-one".