18222138 has 32 divisors (see below), whose sum is σ = 44176320. Its totient is φ = 5521680.

The previous prime is 18222137. The next prime is 18222151. The reversal of 18222138 is 83122281.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18222137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14745 + ... + 15932.

It is an arithmetic number, because the mean of its divisors is an integer number (1380510).

Almost surely, 2^18222138 is an apocalyptic number.

18222138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18222138 is an abundant number, since it is smaller than the sum of its proper divisors (25954182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18222138 is a wasteful number, since it uses less digits than its factorization.

18222138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30699 (or 30693 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 18222138 is about 4268.7396266345. The cubic root of 18222138 is about 263.1478203456.

The spelling of 18222138 in words is "eighteen million, two hundred twenty-two thousand, one hundred thirty-eight".