18801820 has 24 divisors (see below), whose sum is σ = 39572064. Its totient is φ = 7503936.

The previous prime is 18801791. The next prime is 18801823. The reversal of 18801820 is 2810881.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18801823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12214 + ... + 13666.

It is an arithmetic number, because the mean of its divisors is an integer number (1648836).

Almost surely, 2^18801820 is an apocalyptic number.

18801820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18801820 is an abundant number, since it is smaller than the sum of its proper divisors (20770244).

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

18801820 is a wasteful number, since it uses less digits than its factorization.

18801820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2109 (or 2107 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 28.

The square root of 18801820 is about 4336.1065485064. The cubic root of 18801820 is about 265.9091592497.

The spelling of 18801820 in words is "eighteen million, eight hundred one thousand, eight hundred twenty".