6661656 has 32 divisors (see below), whose sum is σ = 18505200. Its totient is φ = 2220480.

The previous prime is 6661649. The next prime is 6661661. The reversal of 6661656 is 6561666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 6661656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15205 + ... + 15636.

Almost surely, 2^6661656 is an apocalyptic number.

It is an amenable number.

6661656 is an abundant number, since it is smaller than the sum of its proper divisors (11843544).

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

6661656 is a wasteful number, since it uses less digits than its factorization.

6661656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30856 (or 30846 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 6661656 is about 2581.0184036539. The cubic root of 6661656 is about 188.1600417795.

The spelling of 6661656 in words is "six million, six hundred sixty-one thousand, six hundred fifty-six".