66979804668 has 96 divisors (see below), whose sum is σ = 183171039744. Its totient is φ = 18650677248.

The previous prime is 66979804649. The next prime is 66979804679. The reversal of 66979804668 is 86640897966.

It is a super-3 number, since 3×66979804668³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1630396 + ... + 1670972.

It is an arithmetic number, because the mean of its divisors is an integer number (1908031664).

Almost surely, 2^66979804668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66979804668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91585519872).

66979804668 is an abundant number, since it is smaller than the sum of its proper divisors (116191235076).

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

66979804668 is a wasteful number, since it uses less digits than its factorization.

66979804668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41091 (or 41089 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 69.

The spelling of 66979804668 in words is "sixty-six billion, nine hundred seventy-nine million, eight hundred four thousand, six hundred sixty-eight".