668444 has 12 divisors (see below), whose sum is σ = 1336944. Its totient is φ = 286464.

The previous prime is 668417. The next prime is 668471. The reversal of 668444 is 444866.

668444 = T₁₅₇ + T₁₅₈ + ... + T₁₉₈.

It is an interprime number because it is at equal distance from previous prime (668417) and next prime (668471).

668444 is an admirable number.

It is a super-2 number, since 2×668444² = 893634762272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 668444.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11909 + ... + 11964.

It is an arithmetic number, because the mean of its divisors is an integer number (111412).

2⁶⁶⁸⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

668444 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

668444 is a wasteful number, since it uses less digits than its factorization.

668444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23884 (or 23882 counting only the distinct ones).

The product of its digits is 18432, while the sum is 32.

The square root of 668444 is about 817.5842464236. The cubic root of 668444 is about 87.4356097705.

The spelling of 668444 in words is "six hundred sixty-eight thousand, four hundred forty-four".