18222820 has 48 divisors (see below), whose sum is σ = 47714688. Its totient is φ = 5679360.

The previous prime is 18222811. The next prime is 18222829. The reversal of 18222820 is 2822281.

It is an interprime number because it is at equal distance from previous prime (18222811) and next prime (18222829).

It is not an unprimeable number, because it can be changed into a prime (18222829) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4377 + ... + 7456.

It is an arithmetic number, because the mean of its divisors is an integer number (994056).

Almost surely, 2^18222820 is an apocalyptic number.

18222820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18222820 is an abundant number, since it is smaller than the sum of its proper divisors (29491868).

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

18222820 is a wasteful number, since it uses less digits than its factorization.

18222820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11860 (or 11858 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 18222820 is about 4268.8195089509. The cubic root of 18222820 is about 263.1511032493.

The spelling of 18222820 in words is "eighteen million, two hundred twenty-two thousand, eight hundred twenty".