18458211321 has 81 divisors (see below), whose sum is σ = 30807690277. Its totient is φ = 10640633520.

The previous prime is 18458211313. The next prime is 18458211323. The reversal of 18458211321 is 12311285481.

It is a happy number.

The square root of 18458211321 is 135861.

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

It is not a de Polignac number, because 18458211321 - 2³ = 18458211313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18458211323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 103118410 + ... + 103118588.

Almost surely, 2^18458211321 is an apocalyptic number.

18458211321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18458211321 is the 135861-st square number.

18458211321 is the 67931-st centered octagonal number.

It is an amenable number.

18458211321 is a deficient number, since it is larger than the sum of its proper divisors (12349478956).

18458211321 is a wasteful number, since it uses less digits than its factorization.

18458211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 216 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

Multiplying 18458211321 by its sum of digits (36), we get a square (664495607556 = 815166²).

The spelling of 18458211321 in words is "eighteen billion, four hundred fifty-eight million, two hundred eleven thousand, three hundred twenty-one".