666220056 has 64 divisors (see below), whose sum is σ = 1689206400. Its totient is φ = 218938368.

The previous prime is 666220031. The next prime is 666220127. The reversal of 666220056 is 650022666.

It is a junction number, because it is equal to n+sod(n) for n = 666219999 and 666220026.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 975091 + ... + 975773.

It is an arithmetic number, because the mean of its divisors is an integer number (26393850).

Almost surely, 2^666220056 is an apocalyptic number.

It is an amenable number.

666220056 is an abundant number, since it is smaller than the sum of its proper divisors (1022986344).

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

666220056 is a wasteful number, since it uses less digits than its factorization.

666220056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208 (or 1204 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 666220056 is about 25811.2389474043. The cubic root of 666220056 is about 873.3853459819.

The spelling of 666220056 in words is "six hundred sixty-six million, two hundred twenty thousand, fifty-six".