668735690 has 16 divisors (see below), whose sum is σ = 1375684992. Its totient is φ = 229280784.

The previous prime is 668735687. The next prime is 668735713. The reversal of 668735690 is 96537866.

668735690 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×668735690² = 894414846159552200, which contains 22 as substring.

It is a Curzon 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, 4776614 + ... + 4776753.

It is an arithmetic number, because the mean of its divisors is an integer number (85980312).

Almost surely, 2^668735690 is an apocalyptic number.

668735690 is an abundant number, since it is smaller than the sum of its proper divisors (706949302).

668735690 is a wasteful number, since it uses less digits than its factorization.

668735690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9553381.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The square root of 668735690 is about 25859.9244005082. The cubic root of 668735690 is about 874.4832606091.

The spelling of 668735690 in words is "six hundred sixty-eight million, seven hundred thirty-five thousand, six hundred ninety".