18821845 has 16 divisors (see below), whose sum is σ = 26046720. Its totient is φ = 12789504.

The previous prime is 18821821. The next prime is 18821849. The reversal of 18821845 is 54812881.

It is a happy number.

It is not a de Polignac number, because 18821845 - 2⁷ = 18821717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1576 + ... + 6334.

It is an arithmetic number, because the mean of its divisors is an integer number (1627920).

Almost surely, 2^18821845 is an apocalyptic number.

It is an amenable number.

18821845 is a deficient number, since it is larger than the sum of its proper divisors (7224875).

18821845 is a wasteful number, since it uses less digits than its factorization.

18821845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4884.

The product of its digits is 20480, while the sum is 37.

The square root of 18821845 is about 4338.4150331659. The cubic root of 18821845 is about 266.0035285114.

The spelling of 18821845 in words is "eighteen million, eight hundred twenty-one thousand, eight hundred forty-five".