668997 has 36 divisors (see below), whose sum is σ = 1182636. Its totient is φ = 362880.

The previous prime is 668989. The next prime is 668999. The reversal of 668997 is 799866.

It can be written as a sum of positive squares in 2 ways, for example, as 298116 + 370881 = 546^2 + 609^2 .

It is not a de Polignac number, because 668997 - 2³ = 668989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668999) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 16297 + ... + 16337.

It is an arithmetic number, because the mean of its divisors is an integer number (32851).

2⁶⁶⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

668997 is a deficient number, since it is larger than the sum of its proper divisors (513639).

668997 is a wasteful number, since it uses less digits than its factorization.

668997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 88 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 668997 is about 817.9223679543. The cubic root of 668997 is about 87.4597147888.

It can be divided in two parts, 6689 and 97, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 668997 in words is "six hundred sixty-eight thousand, nine hundred ninety-seven".