667399 has 4 divisors (see below), whose sum is σ = 688960. Its totient is φ = 645840.

The previous prime is 667379. The next prime is 667417. The reversal of 667399 is 993766.

667399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 667399 - 2⁵ = 667367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667309) 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, 10734 + ... + 10795.

It is an arithmetic number, because the mean of its divisors is an integer number (172240).

2⁶⁶⁷³⁹⁹ is an apocalyptic number.

667399 is a deficient number, since it is larger than the sum of its proper divisors (21561).

667399 is a wasteful number, since it uses less digits than its factorization.

667399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21560.

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

The square root of 667399 is about 816.9449185839. The cubic root of 667399 is about 87.3900223727.

The spelling of 667399 in words is "six hundred sixty-seven thousand, three hundred ninety-nine".