668976 has 80 divisors (see below), whose sum is σ = 2166528. Its totient is φ = 172800.

The previous prime is 668963. The next prime is 668989. The reversal of 668976 is 679866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (668963) and next prime (668989).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

668976 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3606 + ... + 3786.

2⁶⁶⁸⁹⁷⁶ is an apocalyptic number.

668976 is a gapful number since it is divisible by the number (66) 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 668976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1083264).

668976 is an abundant number, since it is smaller than the sum of its proper divisors (1497552).

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

668976 is a wasteful number, since it uses less digits than its factorization.

668976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 204 counting only the distinct ones).

The product of its digits is 108864, while the sum is 42.

The square root of 668976 is about 817.9095304494. The cubic root of 668976 is about 87.4587996510.

It can be divided in two parts, 66 and 8976, that multiplied together give a triangular number (592416 = T₁₀₈₈).

The spelling of 668976 in words is "six hundred sixty-eight thousand, nine hundred seventy-six".