18723563 has 4 divisors (see below), whose sum is σ = 18790008. Its totient is φ = 18657120.

The previous prime is 18723559. The next prime is 18723571. The reversal of 18723563 is 36532781.

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

It is a cyclic number.

It is not a de Polignac number, because 18723563 - 2² = 18723559 is a prime.

It is a super-2 number, since 2×18723563² = 701143622829938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18723503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32798 + ... + 33363.

It is an arithmetic number, because the mean of its divisors is an integer number (4697502).

Almost surely, 2^18723563 is an apocalyptic number.

18723563 is a deficient number, since it is larger than the sum of its proper divisors (66445).

18723563 is an equidigital number, since it uses as much as digits as its factorization.

18723563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66444.

The product of its digits is 30240, while the sum is 35.

The square root of 18723563 is about 4327.0732602996. The cubic root of 18723563 is about 265.5397235461.

The spelling of 18723563 in words is "eighteen million, seven hundred twenty-three thousand, five hundred sixty-three".