18821230 has 16 divisors (see below), whose sum is σ = 33942240. Its totient is φ = 7514272.

The previous prime is 18821219. The next prime is 18821239. The reversal of 18821230 is 3212881.

It is a junction number, because it is equal to n+sod(n) for n = 18821195 and 18821204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5016 + ... + 7924.

It is an arithmetic number, because the mean of its divisors is an integer number (2121390).

Almost surely, 2^18821230 is an apocalyptic number.

18821230 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18821230 is a deficient number, since it is larger than the sum of its proper divisors (15121010).

18821230 is a wasteful number, since it uses less digits than its factorization.

18821230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 18821230 is about 4338.3441541676. The cubic root of 18821230 is about 266.0006312759. Note that the first 3 decimals are identical.

The spelling of 18821230 in words is "eighteen million, eight hundred twenty-one thousand, two hundred thirty".