18223789 has 4 divisors (see below), whose sum is σ = 18264124. Its totient is φ = 18183456.

The previous prime is 18223781. The next prime is 18223817. The reversal of 18223789 is 98732281.

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 9253764 + 8970025 = 3042^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 18223789 - 2³ = 18223781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18223781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19482 + ... + 20395.

It is an arithmetic number, because the mean of its divisors is an integer number (4566031).

Almost surely, 2^18223789 is an apocalyptic number.

It is an amenable number.

18223789 is a deficient number, since it is larger than the sum of its proper divisors (40335).

18223789 is an equidigital number, since it uses as much as digits as its factorization.

18223789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40334.

The product of its digits is 48384, while the sum is 40.

The square root of 18223789 is about 4268.9330048620. The cubic root of 18223789 is about 263.1557675274.

The spelling of 18223789 in words is "eighteen million, two hundred twenty-three thousand, seven hundred eighty-nine".