18532221 has 12 divisors (see below), whose sum is σ = 24970752. Its totient is φ = 12225528.

The previous prime is 18532219. The next prime is 18532223. The reversal of 18532221 is 12223581.

It is an interprime number because it is at equal distance from previous prime (18532219) and next prime (18532223).

It is not a de Polignac number, because 18532221 - 2¹ = 18532219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18532191 and 18532200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18532223) 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, 48196 + ... + 48578.

It is an arithmetic number, because the mean of its divisors is an integer number (2080896).

Almost surely, 2^18532221 is an apocalyptic number.

It is an amenable number.

18532221 is a deficient number, since it is larger than the sum of its proper divisors (6438531).

18532221 is an equidigital number, since it uses as much as digits as its factorization.

18532221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 513 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 18532221 is about 4304.9066191963. The cubic root of 18532221 is about 264.6320799073.

The spelling of 18532221 in words is "eighteen million, five hundred thirty-two thousand, two hundred twenty-one".