18181845 has 48 divisors (see below), whose sum is σ = 35897472. Its totient is φ = 8426880.

The previous prime is 18181831. The next prime is 18181861. The reversal of 18181845 is 54818181.

It is a happy number.

It is not a de Polignac number, because 18181845 - 2⁴ = 18181829 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10587 + ... + 12183.

It is an arithmetic number, because the mean of its divisors is an integer number (747864).

Almost surely, 2^18181845 is an apocalyptic number.

18181845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18181845 is a deficient number, since it is larger than the sum of its proper divisors (17715627).

18181845 is a wasteful number, since it uses less digits than its factorization.

18181845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1642 (or 1639 counting only the distinct ones).

The product of its digits is 10240, while the sum is 36.

The square root of 18181845 is about 4264.0174718216. The cubic root of 18181845 is about 262.9537187184.

It can be divided in two parts, 1818 and 1845, that added together give a palindrome (3663).

The spelling of 18181845 in words is "eighteen million, one hundred eighty-one thousand, eight hundred forty-five".