18406222 has 4 divisors (see below), whose sum is σ = 27609336. Its totient is φ = 9203110.

The previous prime is 18406183. The next prime is 18406229. The reversal of 18406222 is 22260481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22260481 = 23 ⋅967847.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18406229) 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 as a sum of consecutive naturals, namely, 4601554 + ... + 4601557.

It is an arithmetic number, because the mean of its divisors is an integer number (6902334).

Almost surely, 2^18406222 is an apocalyptic number.

18406222 is a deficient number, since it is larger than the sum of its proper divisors (9203114).

18406222 is an equidigital number, since it uses as much as digits as its factorization.

18406222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9203113.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 18406222 is about 4290.2473122187. The cubic root of 18406222 is about 264.0309785349.

The spelling of 18406222 in words is "eighteen million, four hundred six thousand, two hundred twenty-two".