18191222 has 16 divisors (see below), whose sum is σ = 31352832. Its totient is φ = 7754280.

The previous prime is 18191221. The next prime is 18191263. The reversal of 18191222 is 22219181.

It is a junction number, because it is equal to n+sod(n) for n = 18191191 and 18191200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18191221) 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 in 7 ways as a sum of consecutive naturals, for example, 728 + ... + 6075.

It is an arithmetic number, because the mean of its divisors is an integer number (1959552).

Almost surely, 2^18191222 is an apocalyptic number.

18191222 is a deficient number, since it is larger than the sum of its proper divisors (13161610).

18191222 is a wasteful number, since it uses less digits than its factorization.

18191222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7003.

The product of its digits is 576, while the sum is 26.

The square root of 18191222 is about 4265.1168799929. The cubic root of 18191222 is about 262.9989156948.

The spelling of 18191222 in words is "eighteen million, one hundred ninety-one thousand, two hundred twenty-two".