18518582889 has 9 divisors (see below), whose sum is σ = 26749653879. Its totient is φ = 12345449760.

The previous prime is 18518582879. The next prime is 18518582891. The reversal of 18518582889 is 98828581581.

The square root of 18518582889 is 136083.

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

18518582889 is a `hidden beast` number, since 18 + 518 + 5 + 8 + 28 + 89 = 666.

It can be written as a sum of positive squares in only one way, i.e., 98664489 + 18419918400 = 9933^2 + 135720^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 18518582889 - 2⁵ = 18518582857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18518582879) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 385569 + ... + 430929.

Almost surely, 2^18518582889 is an apocalyptic number.

18518582889 is the 136083-rd square number.

18518582889 is the 68042-nd centered octagonal number.

It is an amenable number.

18518582889 is a deficient number, since it is larger than the sum of its proper divisors (8231070990).

18518582889 is an frugal number, since it uses more digits than its factorization.

18518582889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90728 (or 45364 counting only the distinct ones).

The product of its digits is 14745600, while the sum is 63.

The spelling of 18518582889 in words is "eighteen billion, five hundred eighteen million, five hundred eighty-two thousand, eight hundred eighty-nine".