391566 has 16 divisors (see below), whose sum is σ = 895104. Its totient is φ = 111864.

The previous prime is 391553. The next prime is 391579. The reversal of 391566 is 665193.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (391553) and next prime (391579).

It is a congruent number.

It is an unprimeable number.

391566 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4620 + ... + 4703.

It is an arithmetic number, because the mean of its divisors is an integer number (55944).

2³⁹¹⁵⁶⁶ is an apocalyptic number.

391566 is an abundant number, since it is smaller than the sum of its proper divisors (503538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391566 is a wasteful number, since it uses less digits than its factorization.

391566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9335.

The product of its digits is 4860, while the sum is 30.

The square root of 391566 is about 625.7523471790. The cubic root of 391566 is about 73.1590950655.

The spelling of 391566 in words is "three hundred ninety-one thousand, five hundred sixty-six".