669989880 has 384 divisors, whose sum is σ = 2652249600. Its totient is φ = 148925952.

The previous prime is 669989833. The next prime is 669989893. The reversal of 669989880 is 88989966.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2925606 + ... + 2925834.

It is an arithmetic number, because the mean of its divisors is an integer number (6906900).

Almost surely, 2^669989880 is an apocalyptic number.

669989880 is a gapful number since it is divisible by the number (60) 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 669989880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1326124800).

669989880 is an abundant number, since it is smaller than the sum of its proper divisors (1982259720).

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

669989880 is a wasteful number, since it uses less digits than its factorization.

669989880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 13436928, while the sum is 63.

The square root of 669989880 is about 25884.1627254968. The cubic root of 669989880 is about 875.0296066173.

The spelling of 669989880 in words is "six hundred sixty-nine million, nine hundred eighty-nine thousand, eight hundred eighty".