18019575032809 has 27 divisors (see below), whose sum is σ = 21038877656517. Its totient is φ = 15388578106944.

The previous prime is 18019575032777. The next prime is 18019575032831. The reversal of 18019575032809 is 90823057591081.

It is a happy number.

The square root of 18019575032809 is 4244947.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 298337717209 + 17721237315600 = 546203^2 + 4209660^2 .

It is not a de Polignac number, because 18019575032809 - 2⁵ = 18019575032777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18019575032609) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9419536437 + ... + 9419538349.

Almost surely, 2^{18019575032809} is an apocalyptic number.

18019575032809 is the 4244947-th square number.

18019575032809 is the 2122474-th centered octagonal number.

It is an amenable number.

18019575032809 is a deficient number, since it is larger than the sum of its proper divisors (3019302623708).

18019575032809 is an frugal number, since it uses more digits than its factorization.

18019575032809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4474 (or 2237 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 58.

The spelling of 18019575032809 in words is "eighteen trillion, nineteen billion, five hundred seventy-five million, thirty-two thousand, eight hundred nine".