669398520 has 128 divisors (see below), whose sum is σ = 2301120000. Its totient is φ = 152603136.

The previous prime is 669398497. The next prime is 669398573. The reversal of 669398520 is 25893966.

It is a self number, because there is not a number n which added to its sum of digits gives 669398520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 418362 + ... + 419958.

It is an arithmetic number, because the mean of its divisors is an integer number (17977500).

Almost surely, 2^669398520 is an apocalyptic number.

669398520 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 669398520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150560000).

669398520 is an abundant number, since it is smaller than the sum of its proper divisors (1631721480).

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

669398520 is a wasteful number, since it uses less digits than its factorization.

669398520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117 (or 2113 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 48.

The square root of 669398520 is about 25872.7370024897. The cubic root of 669398520 is about 874.7720854013.

The spelling of 669398520 in words is "six hundred sixty-nine million, three hundred ninety-eight thousand, five hundred twenty".