6661661256 has 48 divisors (see below), whose sum is σ = 18179750160. Its totient is φ = 2203599840.

The previous prime is 6661661159. The next prime is 6661661261. The reversal of 6661661256 is 6521661666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 343710 + ... + 362573.

It is an arithmetic number, because the mean of its divisors is an integer number (378744795).

Almost surely, 2^6661661256 is an apocalyptic number.

It is an amenable number.

6661661256 is an abundant number, since it is smaller than the sum of its proper divisors (11518088904).

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

6661661256 is a wasteful number, since it uses less digits than its factorization.

6661661256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706426 (or 706419 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 6661661256 is about 81619.0005819723. Note that the first 3 decimals coincide. The cubic root of 6661661256 is about 1881.6009126510.

The spelling of 6661661256 in words is "six billion, six hundred sixty-one million, six hundred sixty-one thousand, two hundred fifty-six".