18863221 has 8 divisors (see below), whose sum is σ = 20969984. Its totient is φ = 16850160.

The previous prime is 18863191. The next prime is 18863227. The reversal of 18863221 is 12236881.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18863221 - 2⁷ = 18863093 is a prime.

It is a super-2 number, since 2×18863221² = 711642212989682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18863227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23001 + ... + 23806.

It is an arithmetic number, because the mean of its divisors is an integer number (2621248).

Almost surely, 2^18863221 is an apocalyptic number.

It is an amenable number.

18863221 is a deficient number, since it is larger than the sum of its proper divisors (2106763).

18863221 is a wasteful number, since it uses less digits than its factorization.

18863221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46851.

The product of its digits is 4608, while the sum is 31.

The square root of 18863221 is about 4343.1809771180. The cubic root of 18863221 is about 266.1983040837.

The spelling of 18863221 in words is "eighteen million, eight hundred sixty-three thousand, two hundred twenty-one".