668759520 has 192 divisors, whose sum is σ = 2475131904. Its totient is φ = 149637120.

The previous prime is 668759519. The next prime is 668759527. The reversal of 668759520 is 25957866.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 668759520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668759527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63769 + ... + 73511.

It is an arithmetic number, because the mean of its divisors is an integer number (12891312).

Almost surely, 2^668759520 is an apocalyptic number.

668759520 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 668759520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1237565952).

668759520 is an abundant number, since it is smaller than the sum of its proper divisors (1806372384).

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

668759520 is a wasteful number, since it uses less digits than its factorization.

668759520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9785 (or 9777 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 48.

The square root of 668759520 is about 25860.3851479439. The cubic root of 668759520 is about 874.4936477166.

The spelling of 668759520 in words is "six hundred sixty-eight million, seven hundred fifty-nine thousand, five hundred twenty".