667438 has 4 divisors (see below), whose sum is σ = 1001160. Its totient is φ = 333718.

The previous prime is 667427. The next prime is 667441. The reversal of 667438 is 834766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 834766 = 2 ⋅417383.

It is a congruent number.

It is an unprimeable number.

667438 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166858 + ... + 166861.

It is an arithmetic number, because the mean of its divisors is an integer number (250290).

2⁶⁶⁷⁴³⁸ is an apocalyptic number.

667438 is a deficient number, since it is larger than the sum of its proper divisors (333722).

667438 is a wasteful number, since it uses less digits than its factorization.

667438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333721.

The product of its digits is 24192, while the sum is 34.

The square root of 667438 is about 816.9687876535. The cubic root of 667438 is about 87.3917245750.

The spelling of 667438 in words is "six hundred sixty-seven thousand, four hundred thirty-eight".