668635490 has 16 divisors (see below), whose sum is σ = 1204474752. Its totient is φ = 267247344.

The previous prime is 668635477. The next prime is 668635493. The reversal of 668635490 is 94536866.

668635490 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668635493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11924 + ... + 38463.

It is an arithmetic number, because the mean of its divisors is an integer number (75279672).

Almost surely, 2^668635490 is an apocalyptic number.

668635490 is a deficient number, since it is larger than the sum of its proper divisors (535839262).

668635490 is a wasteful number, since it uses less digits than its factorization.

668635490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51721.

The product of its (nonzero) digits is 933120, while the sum is 47.

The square root of 668635490 is about 25857.9869672796. The cubic root of 668635490 is about 874.4395823663.

The spelling of 668635490 in words is "six hundred sixty-eight million, six hundred thirty-five thousand, four hundred ninety".