668520 has 64 divisors (see below), whose sum is σ = 2232000. Its totient is φ = 177984.

The previous prime is 668513. The next prime is 668527. The reversal of 668520 is 25866.

It is an interprime number because it is at equal distance from previous prime (668513) and next prime (668527).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (668527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 771 + ... + 1389.

It is an arithmetic number, because the mean of its divisors is an integer number (34875).

2⁶⁶⁸⁵²⁰ is an apocalyptic number.

668520 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 668520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1116000).

668520 is an abundant number, since it is smaller than the sum of its proper divisors (1563480).

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

668520 is a wasteful number, since it uses less digits than its factorization.

668520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639 (or 629 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 668520 is about 817.6307234932. The cubic root of 668520 is about 87.4389233637.

The spelling of 668520 in words is "six hundred sixty-eight thousand, five hundred twenty".