18241820 has 24 divisors (see below), whose sum is σ = 38706864. Its totient is φ = 7220736.

The previous prime is 18241813. The next prime is 18241831. The reversal of 18241820 is 2814281.

It is a self number, because there is not a number n which added to its sum of digits gives 18241820.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2762 + ... + 6641.

It is an arithmetic number, because the mean of its divisors is an integer number (1612786).

Almost surely, 2^18241820 is an apocalyptic number.

18241820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18241820 is an abundant number, since it is smaller than the sum of its proper divisors (20465044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18241820 is a wasteful number, since it uses less digits than its factorization.

18241820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9509 (or 9507 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 18241820 is about 4271.0443687698. The cubic root of 18241820 is about 263.2425295354.

The spelling of 18241820 in words is "eighteen million, two hundred forty-one thousand, eight hundred twenty".