18191330 has 16 divisors (see below), whose sum is σ = 33160320. Its totient is φ = 7184112.

The previous prime is 18191317. The next prime is 18191339. The reversal of 18191330 is 3319181.

It is a self number, because there is not a number n which added to its sum of digits gives 18191330.

It is not an unprimeable number, because it can be changed into a prime (18191339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10724 + ... + 12303.

It is an arithmetic number, because the mean of its divisors is an integer number (2072520).

Almost surely, 2^18191330 is an apocalyptic number.

18191330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18191330 is a deficient number, since it is larger than the sum of its proper divisors (14968990).

18191330 is a wasteful number, since it uses less digits than its factorization.

18191330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23113.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 18191330 is about 4265.1295408229. The cubic root of 18191330 is about 262.9994361624. Note that the first 3 decimals are identical.

The spelling of 18191330 in words is "eighteen million, one hundred ninety-one thousand, three hundred thirty".