391563 has 12 divisors (see below), whose sum is σ = 571480. Its totient is φ = 258336.

The previous prime is 391553. The next prime is 391579. The reversal of 391563 is 365193.

It is not a de Polignac number, because 391563 - 2¹⁰ = 390539 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 (391553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1095 + ... + 1407.

2³⁹¹⁵⁶³ is an apocalyptic number.

391563 is a deficient number, since it is larger than the sum of its proper divisors (179917).

391563 is a wasteful number, since it uses less digits than its factorization.

391563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 455 counting only the distinct ones).

The product of its digits is 2430, while the sum is 27.

The square root of 391563 is about 625.7499500599. The cubic root of 391563 is about 73.1589082278.

The spelling of 391563 in words is "three hundred ninety-one thousand, five hundred sixty-three".