669980864 has 84 divisors (see below), whose sum is σ = 1554729936. Its totient is φ = 280610304.

The previous prime is 669980851. The next prime is 669980891. The reversal of 669980864 is 468089966.

669980864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 989294 + ... + 989970.

Almost surely, 2^669980864 is an apocalyptic number.

669980864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669980864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777364968).

669980864 is an abundant number, since it is smaller than the sum of its proper divisors (884749072).

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

669980864 is an equidigital number, since it uses as much as digits as its factorization.

669980864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 733 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 56.

The square root of 669980864 is about 25883.9885643616. The cubic root of 669980864 is about 875.0256815319.

The spelling of 669980864 in words is "six hundred sixty-nine million, nine hundred eighty thousand, eight hundred sixty-four".