666986965888 has 64 divisors (see below), whose sum is σ = 1407279801600. Its totient is φ = 314002718208.

The previous prime is 666986965837. The next prime is 666986965891. The reversal of 666986965888 is 888569689666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×666986965888² (a number of 24 digits) contains 22 as substring.

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, 444856 + ... + 1237687.

It is an arithmetic number, because the mean of its divisors is an integer number (21988746900).

Almost surely, 2^666986965888 is an apocalyptic number.

It is an amenable number.

666986965888 is an abundant number, since it is smaller than the sum of its proper divisors (740292835712).

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

666986965888 is a wasteful number, since it uses less digits than its factorization.

666986965888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1682739 (or 1682727 counting only the distinct ones).

The product of its digits is 12899450880, while the sum is 85.

The spelling of 666986965888 in words is "six hundred sixty-six billion, nine hundred eighty-six million, nine hundred sixty-five thousand, eight hundred eighty-eight".