666913520 has 240 divisors, whose sum is σ = 2030495040. Its totient is φ = 201535488.

The previous prime is 666913517. The next prime is 666913537. The reversal of 666913520 is 25319666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1171796 + ... + 1172364.

It is an arithmetic number, because the mean of its divisors is an integer number (8460396).

Almost surely, 2^666913520 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 666913520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1015247520).

666913520 is an abundant number, since it is smaller than the sum of its proper divisors (1363581520).

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

666913520 is a wasteful number, since it uses less digits than its factorization.

666913520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 619 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 666913520 is about 25824.6688265310. The cubic root of 666913520 is about 873.6882745556.

The spelling of 666913520 in words is "six hundred sixty-six million, nine hundred thirteen thousand, five hundred twenty".