1666655660 has 12 divisors (see below), whose sum is σ = 3499976928. Its totient is φ = 666662256.

The previous prime is 1666655621. The next prime is 1666655681. The reversal of 1666655660 is 665566661.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41666372 + ... + 41666411.

It is an arithmetic number, because the mean of its divisors is an integer number (291664744).

Almost surely, 2^1666655660 is an apocalyptic number.

1666655660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666655660 is an abundant number, since it is smaller than the sum of its proper divisors (1833321268).

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

1666655660 is a wasteful number, since it uses less digits than its factorization.

1666655660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83332792 (or 83332790 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 47.

The square root of 1666655660 is about 40824.6942425782. The cubic root of 1666655660 is about 1185.6284915217.

The spelling of 1666655660 in words is "one billion, six hundred sixty-six million, six hundred fifty-five thousand, six hundred sixty".