18256563 has 24 divisors (see below), whose sum is σ = 29294640. Its totient is φ = 11232000.

The previous prime is 18256561. The next prime is 18256649. The reversal of 18256563 is 36565281.

It is not a de Polignac number, because 18256563 - 2¹ = 18256561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18256561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2563 + ... + 6563.

It is an arithmetic number, because the mean of its divisors is an integer number (1220610).

Almost surely, 2^18256563 is an apocalyptic number.

18256563 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18256563 is a deficient number, since it is larger than the sum of its proper divisors (11038077).

18256563 is a wasteful number, since it uses less digits than its factorization.

18256563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4036 (or 4017 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 18256563 is about 4272.7699446612. The cubic root of 18256563 is about 263.3134277891.

The spelling of 18256563 in words is "eighteen million, two hundred fifty-six thousand, five hundred sixty-three".