18228990289 has 4 divisors (see below), whose sum is σ = 18572933556. Its totient is φ = 17885047024.

The previous prime is 18228990257. The next prime is 18228990313. The reversal of 18228990289 is 98209982281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8534618689 + 9694371600 = 92383^2 + 98460^2 .

It is a cyclic number.

It is not a de Polignac number, because 18228990289 - 2⁵ = 18228990257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18228990589) 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, 171971554 + ... + 171971659.

It is an arithmetic number, because the mean of its divisors is an integer number (4643233389).

Almost surely, 2^18228990289 is an apocalyptic number.

It is an amenable number.

18228990289 is a deficient number, since it is larger than the sum of its proper divisors (343943267).

18228990289 is an equidigital number, since it uses as much as digits as its factorization.

18228990289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343943266.

The product of its (nonzero) digits is 2985984, while the sum is 58.

The spelling of 18228990289 in words is "eighteen billion, two hundred twenty-eight million, nine hundred ninety thousand, two hundred eighty-nine".