6621610666 has 16 divisors (see below), whose sum is σ = 10839536640. Its totient is φ = 3008663680.

The previous prime is 6621610607. The next prime is 6621610673. The reversal of 6621610666 is 6660161266.

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, 1815 + ... + 115093.

It is an arithmetic number, because the mean of its divisors is an integer number (677471040).

Almost surely, 2^6621610666 is an apocalyptic number.

6621610666 is a deficient number, since it is larger than the sum of its proper divisors (4217925974).

6621610666 is a wasteful number, since it uses less digits than its factorization.

6621610666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115949.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 6621610666 is about 81373.2798036309. The cubic root of 6621610666 is about 1877.8225380227.

The spelling of 6621610666 in words is "six billion, six hundred twenty-one million, six hundred ten thousand, six hundred sixty-six".