18000022 has 4 divisors (see below), whose sum is σ = 27000036. Its totient is φ = 9000010.

The previous prime is 17999987. The next prime is 18000041. The reversal of 18000022 is 22000081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22000081 = 19 ⋅1157899.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

18000022 is a modest number, since divided by 22 gives 18 as remainder.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 17999966 and 18000011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4500004 + ... + 4500007.

It is an arithmetic number, because the mean of its divisors is an integer number (6750009).

Almost surely, 2^18000022 is an apocalyptic number.

18000022 is a deficient number, since it is larger than the sum of its proper divisors (9000014).

18000022 is an equidigital number, since it uses as much as digits as its factorization.

18000022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9000013.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 18000022 is about 4242.6432798434. The cubic root of 18000022 is about 262.0742461918.

The spelling of 18000022 in words is "eighteen million, twenty-two", and thus it is an aban number and an uban number.