18321231361 has 4 divisors (see below), whose sum is σ = 18321508800. Its totient is φ = 18320953924.

The previous prime is 18321231329. The next prime is 18321231367. The reversal of 18321231361 is 16313212381.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18321231361 - 2⁵ = 18321231329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18321231367) 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, 23820 + ... + 192898.

It is an arithmetic number, because the mean of its divisors is an integer number (4580377200).

Almost surely, 2^18321231361 is an apocalyptic number.

It is an amenable number.

18321231361 is a deficient number, since it is larger than the sum of its proper divisors (277439).

18321231361 is a wasteful number, since it uses less digits than its factorization.

18321231361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277438.

The product of its digits is 5184, while the sum is 31.

The spelling of 18321231361 in words is "eighteen billion, three hundred twenty-one million, two hundred thirty-one thousand, three hundred sixty-one".