666976 has 24 divisors (see below), whose sum is σ = 1383480. Its totient is φ = 315648.

The previous prime is 666959. The next prime is 666979. The reversal of 666976 is 679666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60 + ... + 1156.

It is an arithmetic number, because the mean of its divisors is an integer number (57645).

2⁶⁶⁶⁹⁷⁶ 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 666976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (691740).

666976 is an abundant number, since it is smaller than the sum of its proper divisors (716504).

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

666976 is a wasteful number, since it uses less digits than its factorization.

666976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126 (or 1118 counting only the distinct ones).

The product of its digits is 81648, while the sum is 40.

The square root of 666976 is about 816.6859861660. The cubic root of 666976 is about 87.3715557623.

It can be divided in two parts, 6 and 66976, that multiplied together give a triangular number (401856 = T₈₉₆).

The spelling of 666976 in words is "six hundred sixty-six thousand, nine hundred seventy-six".