668999505 has 64 divisors (see below), whose sum is σ = 1151926272. Its totient is φ = 330781440.

The previous prime is 668999497. The next prime is 668999509. The reversal of 668999505 is 505999866.

668999505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 668999505 - 2³ = 668999497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668999509) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1746544 + ... + 1746926.

It is an arithmetic number, because the mean of its divisors is an integer number (17998848).

Almost surely, 2^668999505 is an apocalyptic number.

It is an amenable number.

668999505 is a deficient number, since it is larger than the sum of its proper divisors (482926767).

668999505 is a wasteful number, since it uses less digits than its factorization.

668999505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558.

The product of its (nonzero) digits is 5248800, while the sum is 57.

The square root of 668999505 is about 25865.0247438505. The cubic root of 668999505 is about 874.5982395035.

The spelling of 668999505 in words is "six hundred sixty-eight million, nine hundred ninety-nine thousand, five hundred five".