667939 has 4 divisors (see below), whose sum is σ = 679320. Its totient is φ = 656560.

The previous prime is 667921. The next prime is 667949. The reversal of 667939 is 939766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 667939 - 2⁹ = 667427 is a prime.

It is a super-2 number, since 2×667939² = 892285015442, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 14.

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 3 ways as a sum of consecutive naturals, for example, 5602 + ... + 5719.

It is an arithmetic number, because the mean of its divisors is an integer number (169830).

2⁶⁶⁷⁹³⁹ is an apocalyptic number.

667939 is a deficient number, since it is larger than the sum of its proper divisors (11381).

667939 is a wasteful number, since it uses less digits than its factorization.

667939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11380.

The product of its digits is 61236, while the sum is 40.

The square root of 667939 is about 817.2753513963. The cubic root of 667939 is about 87.4135854338.

The spelling of 667939 in words is "six hundred sixty-seven thousand, nine hundred thirty-nine".