667994 has 4 divisors (see below), whose sum is σ = 1001994. Its totient is φ = 333996.

The previous prime is 667991. The next prime is 667999. The reversal of 667994 is 499766.

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

It can be written as a sum of positive squares in only one way, i.e., 570025 + 97969 = 755^2 + 313^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (667991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166997 + ... + 167000.

2⁶⁶⁷⁹⁹⁴ is an apocalyptic number.

667994 is a deficient number, since it is larger than the sum of its proper divisors (334000).

667994 is a wasteful number, since it uses less digits than its factorization.

667994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333999.

The product of its digits is 81648, while the sum is 41.

The square root of 667994 is about 817.3089990940. The cubic root of 667994 is about 87.4159846625.

It can be divided in two parts, 667 and 994, that added together give a palindrome (1661).

The spelling of 667994 in words is "six hundred sixty-seven thousand, nine hundred ninety-four".