669957988 has 72 divisors (see below), whose sum is σ = 1428585984. Its totient is φ = 273772800.

The previous prime is 669957983. The next prime is 669957997. The reversal of 669957988 is 889759966.

It is not an unprimeable number, because it can be changed into a prime (669957983) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 430620 + ... + 432172.

It is an arithmetic number, because the mean of its divisors is an integer number (19841472).

Almost surely, 2^669957988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669957988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714292992).

669957988 is an abundant number, since it is smaller than the sum of its proper divisors (758627996).

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

669957988 is a wasteful number, since it uses less digits than its factorization.

669957988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1673 (or 1664 counting only the distinct ones).

The product of its digits is 58786560, while the sum is 67.

The square root of 669957988 is about 25883.5466657875. The cubic root of 669957988 is about 875.0157223842.

The spelling of 669957988 in words is "six hundred sixty-nine million, nine hundred fifty-seven thousand, nine hundred eighty-eight".