667944 has 24 divisors (see below), whose sum is σ = 1809210. Its totient is φ = 222624.

The previous prime is 667921. The next prime is 667949. The reversal of 667944 is 449766.

It can be written as a sum of positive squares in only one way, i.e., 476100 + 191844 = 690^2 + 438^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×667944² = 892298374272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 667899 and 667908.

It is not an unprimeable number, because it can be changed into a prime (667949) by changing a digit.

667944 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4567 + ... + 4710.

2⁶⁶⁷⁹⁴⁴ is an apocalyptic number.

It is an amenable number.

667944 is an abundant number, since it is smaller than the sum of its proper divisors (1141266).

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

667944 is a wasteful number, since it uses less digits than its factorization.

667944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9289 (or 9282 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 667944 is about 817.2784103352. The cubic root of 667944 is about 87.4138035509.

The spelling of 667944 in words is "six hundred sixty-seven thousand, nine hundred forty-four".