563991 has 8 divisors (see below), whose sum is σ = 772464. Its totient is φ = 365760.

The previous prime is 563987. The next prime is 563999. The reversal of 563991 is 199365.

563991 = 105² + 106² + ... + 141².

563991 is digitally balanced in base 2 and base 7, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 563991 - 2² = 563987 is a prime.

563991 is strictly pandigital in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (563999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2430 + ... + 2651.

It is an arithmetic number, because the mean of its divisors is an integer number (96558).

2⁵⁶³⁹⁹¹ is an apocalyptic number.

563991 is a deficient number, since it is larger than the sum of its proper divisors (208473).

563991 is a wasteful number, since it uses less digits than its factorization.

563991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5121.

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

The square root of 563991 is about 750.9933421809. The cubic root of 563991 is about 82.6210527783.

The spelling of 563991 in words is "five hundred sixty-three thousand, nine hundred ninety-one".