18231845 has 4 divisors (see below), whose sum is σ = 21878220. Its totient is φ = 14585472.

The previous prime is 18231827. The next prime is 18231853. The reversal of 18231845 is 54813281.

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 3247204 + 14984641 = 1802^2 + 3871^2 .

It is a cyclic number.

It is not a de Polignac number, because 18231845 - 2⁶ = 18231781 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1823180 + ... + 1823189.

It is an arithmetic number, because the mean of its divisors is an integer number (5469555).

Almost surely, 2^18231845 is an apocalyptic number.

It is an amenable number.

18231845 is a deficient number, since it is larger than the sum of its proper divisors (3646375).

18231845 is an equidigital number, since it uses as much as digits as its factorization.

18231845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646374.

The product of its digits is 7680, while the sum is 32.

The square root of 18231845 is about 4269.8764619132. The cubic root of 18231845 is about 263.1945386551.

The spelling of 18231845 in words is "eighteen million, two hundred thirty-one thousand, eight hundred forty-five".