18419220 has 36 divisors (see below), whose sum is σ = 55872180. Its totient is φ = 4911744.

The previous prime is 18419207. The next prime is 18419221. The reversal of 18419220 is 2291481.

It can be written as a sum of positive squares in 2 ways, for example, as 5588496 + 12830724 = 2364^2 + 3582^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18419221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50985 + ... + 51344.

It is an arithmetic number, because the mean of its divisors is an integer number (1552005).

Almost surely, 2^18419220 is an apocalyptic number.

18419220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18419220 is an abundant number, since it is smaller than the sum of its proper divisors (37452960).

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

18419220 is a wasteful number, since it uses less digits than its factorization.

18419220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102344 (or 102339 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 18419220 is about 4291.7618759666. The cubic root of 18419220 is about 264.0931145369.

The spelling of 18419220 in words is "eighteen million, four hundred nineteen thousand, two hundred twenty".