391255563 has 4 divisors (see below), whose sum is σ = 521674088. Its totient is φ = 260837040.

The previous prime is 391255541. The next prime is 391255597. The reversal of 391255563 is 365552193.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 391255563 - 2¹⁶ = 391190027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391255463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65209258 + ... + 65209263.

It is an arithmetic number, because the mean of its divisors is an integer number (130418522).

Almost surely, 2^391255563 is an apocalyptic number.

391255563 is a deficient number, since it is larger than the sum of its proper divisors (130418525).

391255563 is a wasteful number, since it uses less digits than its factorization.

391255563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130418524.

The product of its digits is 121500, while the sum is 39.

The square root of 391255563 is about 19780.1810659053. The cubic root of 391255563 is about 731.3975622727.

The spelling of 391255563 in words is "three hundred ninety-one million, two hundred fifty-five thousand, five hundred sixty-three".