667990 has 16 divisors (see below), whose sum is σ = 1221552. Its totient is φ = 262944.

The previous prime is 667987. The next prime is 667991. The reversal of 667990 is 99766.

It is a congruent 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 in 7 ways as a sum of consecutive naturals, for example, 172 + ... + 1168.

It is an arithmetic number, because the mean of its divisors is an integer number (76347).

2⁶⁶⁷⁹⁹⁰ is an apocalyptic number.

667990 is a deficient number, since it is larger than the sum of its proper divisors (553562).

667990 is a wasteful number, since it uses less digits than its factorization.

667990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 667990 is about 817.3065520354. The cubic root of 667990 is about 87.4158101776.

The spelling of 667990 in words is "six hundred sixty-seven thousand, nine hundred ninety".