18365399361 has 27 divisors (see below), whose sum is σ = 26779744641. Its totient is φ = 12128408424.

The previous prime is 18365399359. The next prime is 18365399383. The reversal of 18365399361 is 16399356381.

The square root of 18365399361 is 135519.

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

18365399361 is a `hidden beast` number, since 18 + 3 + 6 + 539 + 93 + 6 + 1 = 666.

It is not a de Polignac number, because 18365399361 - 2¹ = 18365399359 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18365399298 and 18365399307.

It is not an unprimeable number, because it can be changed into a prime (18365399321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 80904730 + ... + 80904956.

Almost surely, 2^18365399361 is an apocalyptic number.

18365399361 is the 135519-th square number.

18365399361 is the 67760-th centered octagonal number.

It is an amenable number.

18365399361 is a deficient number, since it is larger than the sum of its proper divisors (8414345280).

18365399361 is an frugal number, since it uses more digits than its factorization.

18365399361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 858 (or 429 counting only the distinct ones).

The product of its digits is 3149280, while the sum is 54.

The spelling of 18365399361 in words is "eighteen billion, three hundred sixty-five million, three hundred ninety-nine thousand, three hundred sixty-one".