18973220 has 48 divisors (see below), whose sum is σ = 46327680. Its totient is φ = 6392064.

The previous prime is 18973217. The next prime is 18973223. The reversal of 18973220 is 2237981.

It is an interprime number because it is at equal distance from previous prime (18973217) and next prime (18973223).

It is not an unprimeable number, because it can be changed into a prime (18973223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7112 + ... + 9408.

It is an arithmetic number, because the mean of its divisors is an integer number (965160).

Almost surely, 2^18973220 is an apocalyptic number.

18973220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18973220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23163840).

18973220 is an abundant number, since it is smaller than the sum of its proper divisors (27354460).

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

18973220 is a wasteful number, since it uses less digits than its factorization.

18973220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2372 (or 2370 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 18973220 is about 4355.8259836683. The cubic root of 18973220 is about 266.7147378616.

The spelling of 18973220 in words is "eighteen million, nine hundred seventy-three thousand, two hundred twenty".