668666694 has 8 divisors (see below), whose sum is σ = 1337333400. Its totient is φ = 222888896.

The previous prime is 668666693. The next prime is 668666737. The reversal of 668666694 is 496666866.

It is a sphenic number, since it is the product of 3 distinct primes.

668666694 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668666693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55722219 + ... + 55722230.

It is an arithmetic number, because the mean of its divisors is an integer number (167166675).

Almost surely, 2^668666694 is an apocalyptic number.

668666694 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

668666694 is a wasteful number, since it uses less digits than its factorization.

668666694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111444454.

The product of its digits is 13436928, while the sum is 57.

The square root of 668666694 is about 25858.5903328082. The cubic root of 668666694 is about 874.4531849887.

The spelling of 668666694 in words is "six hundred sixty-eight million, six hundred sixty-six thousand, six hundred ninety-four".