669231978 has 16 divisors (see below), whose sum is σ = 1338884640. Its totient is φ = 223007216.

The previous prime is 669231977. The next prime is 669232009. The reversal of 669231978 is 879132966.

It is a self number, because there is not a number n which added to its sum of digits gives 669231978.

It is not an unprimeable number, because it can be changed into a prime (669231973) 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, 5476 + ... + 36992.

It is an arithmetic number, because the mean of its divisors is an integer number (83680290).

Almost surely, 2^669231978 is an apocalyptic number.

669231978 is an abundant number, since it is smaller than the sum of its proper divisors (669652662).

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

669231978 is a wasteful number, since it uses less digits than its factorization.

669231978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35061.

The product of its digits is 979776, while the sum is 51.

The square root of 669231978 is about 25869.5183178968. The cubic root of 669231978 is about 874.6995335148.

The spelling of 669231978 in words is "six hundred sixty-nine million, two hundred thirty-one thousand, nine hundred seventy-eight".