668984 has 16 divisors (see below), whose sum is σ = 1328400. Its totient is φ = 314752.

The previous prime is 668963. The next prime is 668989. The reversal of 668984 is 489866.

668984 = T₂₇₂ + T₂₇₃ + ... + T₂₈₈.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668989) 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, 2324 + ... + 2595.

It is an arithmetic number, because the mean of its divisors is an integer number (83025).

2⁶⁶⁸⁹⁸⁴ is an apocalyptic number.

It is an amenable number.

668984 is a deficient number, since it is larger than the sum of its proper divisors (659416).

668984 is a wasteful number, since it uses less digits than its factorization.

668984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4942 (or 4938 counting only the distinct ones).

The product of its digits is 82944, while the sum is 41.

The square root of 668984 is about 817.9144209512. The cubic root of 668984 is about 87.4591482772.

The spelling of 668984 in words is "six hundred sixty-eight thousand, nine hundred eighty-four".