667945 has 16 divisors (see below), whose sum is σ = 864000. Its totient is φ = 494208.

The previous prime is 667921. The next prime is 667949. The reversal of 667945 is 549766.

667945 is nontrivially palindromic in base 9.

It is a cyclic number.

It is not a de Polignac number, because 667945 - 2⁷ = 667817 is a prime.

It is a super-3 number, since 3×667945³ = 894012033305800875, which contains 333 as substring.

It is a congruent number.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7461 + ... + 7549.

It is an arithmetic number, because the mean of its divisors is an integer number (54000).

2⁶⁶⁷⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

667945 is a deficient number, since it is larger than the sum of its proper divisors (196055).

667945 is a wasteful number, since it uses less digits than its factorization.

667945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192.

The product of its digits is 45360, while the sum is 37.

The square root of 667945 is about 817.2790221216. The cubic root of 667945 is about 87.4138471742.

Multiplying 667945 by its sum of digits (37), we get a triangular number (24713965 = T₇₀₃₀).

It can be divided in two parts, 6679 and 45, that added together give a square (6724 = 82²).

The spelling of 667945 in words is "six hundred sixty-seven thousand, nine hundred forty-five".