18872220 has 48 divisors (see below), whose sum is σ = 54276768. Its totient is φ = 4896000.

The previous prime is 18872219. The next prime is 18872221. The reversal of 18872220 is 2227881.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18872219) and next prime (18872221).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18872221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2031 + ... + 6470.

It is an arithmetic number, because the mean of its divisors is an integer number (1130766).

Almost surely, 2^18872220 is an apocalyptic number.

18872220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18872220 is an abundant number, since it is smaller than the sum of its proper divisors (35404548).

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

18872220 is a wasteful number, since it uses less digits than its factorization.

18872220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8550 (or 8548 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18872220 is about 4344.2168454164. The cubic root of 18872220 is about 266.2406287341.

The spelling of 18872220 in words is "eighteen million, eight hundred seventy-two thousand, two hundred twenty".