391667 has 4 divisors (see below), whose sum is σ = 408720. Its totient is φ = 374616.

The previous prime is 391661. The next prime is 391679. The reversal of 391667 is 766193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 766193 = 701 ⋅1093.

It is a cyclic number.

It is not a de Polignac number, because 391667 - 2¹⁴ = 375283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391661) 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, 8492 + ... + 8537.

It is an arithmetic number, because the mean of its divisors is an integer number (102180).

2³⁹¹⁶⁶⁷ is an apocalyptic number.

391667 is a deficient number, since it is larger than the sum of its proper divisors (17053).

391667 is a wasteful number, since it uses less digits than its factorization.

391667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17052.

The product of its digits is 6804, while the sum is 32.

The square root of 391667 is about 625.8330448291. The cubic root of 391667 is about 73.1653847104.

The spelling of 391667 in words is "three hundred ninety-one thousand, six hundred sixty-seven".