668129930 has 16 divisors (see below), whose sum is σ = 1295144424. Its totient is φ = 246694080.

The previous prime is 668129911. The next prime is 668129941. The reversal of 668129930 is 39921866.

It can be written as a sum of positive squares in 4 ways, for example, as 461949049 + 206180881 = 21493^2 + 14359^2 .

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, 2569601 + ... + 2569860.

Almost surely, 2^668129930 is an apocalyptic number.

668129930 is a deficient number, since it is larger than the sum of its proper divisors (627014494).

668129930 is a wasteful number, since it uses less digits than its factorization.

668129930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5139481.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 668129930 is about 25848.2094157410. The cubic root of 668129930 is about 874.2191368226.

The spelling of 668129930 in words is "six hundred sixty-eight million, one hundred twenty-nine thousand, nine hundred thirty".