18225820 has 12 divisors (see below), whose sum is σ = 38274264. Its totient is φ = 7290320.

The previous prime is 18225811. The next prime is 18225839. The reversal of 18225820 is 2852281.

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 3 ways as a sum of consecutive naturals, for example, 455626 + ... + 455665.

It is an arithmetic number, because the mean of its divisors is an integer number (3189522).

Almost surely, 2^18225820 is an apocalyptic number.

18225820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18225820 is an abundant number, since it is smaller than the sum of its proper divisors (20048444).

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

18225820 is a wasteful number, since it uses less digits than its factorization.

18225820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911300 (or 911298 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 18225820 is about 4269.1708796908. The cubic root of 18225820 is about 263.1655432023.

The spelling of 18225820 in words is "eighteen million, two hundred twenty-five thousand, eight hundred twenty".