18001845 has 20 divisors (see below), whose sum is σ = 32270700. Its totient is φ = 9600768.

The previous prime is 18001843. The next prime is 18001849. The reversal of 18001845 is 54810081.

It can be written as a sum of positive squares in 2 ways, for example, as 11329956 + 6671889 = 3366^2 + 2583^2 .

It is not a de Polignac number, because 18001845 - 2¹ = 18001843 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

18001845 is a modest number, since divided by 1845 gives 180 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18001843) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 21820 + ... + 22629.

It is an arithmetic number, because the mean of its divisors is an integer number (1613535).

Almost surely, 2^18001845 is an apocalyptic number.

18001845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18001845 is a deficient number, since it is larger than the sum of its proper divisors (14268855).

18001845 is an equidigital number, since it uses as much as digits as its factorization.

18001845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44466 (or 44457 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 18001845 is about 4242.8581168830. The cubic root of 18001845 is about 262.0830933147.

The spelling of 18001845 in words is "eighteen million, one thousand, eight hundred forty-five".