668740668 has 48 divisors (see below), whose sum is σ = 1622390784. Its totient is φ = 214220160.

The previous prime is 668740643. The next prime is 668740673. The reversal of 668740668 is 866047866.

It is a self number, because there is not a number n which added to its sum of digits gives 668740668.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22821 + ... + 43107.

It is an arithmetic number, because the mean of its divisors is an integer number (33799808).

Almost surely, 2^668740668 is an apocalyptic number.

It is an amenable number.

668740668 is an abundant number, since it is smaller than the sum of its proper divisors (953650116).

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

668740668 is a wasteful number, since it uses less digits than its factorization.

668740668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20402 (or 20400 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 51.

The square root of 668740668 is about 25860.0206496437. The cubic root of 668740668 is about 874.4854304583.

The spelling of 668740668 in words is "six hundred sixty-eight million, seven hundred forty thousand, six hundred sixty-eight".