391659 has 4 divisors (see below), whose sum is σ = 522216. Its totient is φ = 261104.

The previous prime is 391639. The next prime is 391661. The reversal of 391659 is 956193.

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 391659 - 2⁵ = 391627 is a prime.

It is a D-number.

391659 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (391619) 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, 65274 + ... + 65279.

It is an arithmetic number, because the mean of its divisors is an integer number (130554).

2³⁹¹⁶⁵⁹ is an apocalyptic number.

391659 is a deficient number, since it is larger than the sum of its proper divisors (130557).

391659 is a wasteful number, since it uses less digits than its factorization.

391659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130556.

The product of its digits is 7290, while the sum is 33.

The square root of 391659 is about 625.8266533154. The cubic root of 391659 is about 73.1648865602.

The spelling of 391659 in words is "three hundred ninety-one thousand, six hundred fifty-nine".