18433221361 has 9 divisors (see below), whose sum is σ = 19272776089. Its totient is φ = 17628790036.

The previous prime is 18433221341. The next prime is 18433221419. The reversal of 18433221361 is 16312233481.

The square root of 18433221361 is 135769.

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

It is not a de Polignac number, because 18433221361 - 2¹⁷ = 18433090289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18433221341) 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, 3119736 + ... + 3125638.

Almost surely, 2^18433221361 is an apocalyptic number.

18433221361 is the 135769-th square number.

18433221361 is the 67885-th centered octagonal number.

It is an amenable number.

18433221361 is a deficient number, since it is larger than the sum of its proper divisors (839554728).

18433221361 is an frugal number, since it uses more digits than its factorization.

18433221361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11852 (or 5926 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

Multiplying 18433221361 by its product of digits (20736), we get a square (382231278141696 = 19550736²).

The spelling of 18433221361 in words is "eighteen billion, four hundred thirty-three million, two hundred twenty-one thousand, three hundred sixty-one".