18190000 has 100 divisors (see below), whose sum is σ = 47066184. Its totient is φ = 6784000.

The previous prime is 18189991. The next prime is 18190001. The reversal of 18190000 is 9181.

It is a tau number, because it is divible by the number of its divisors (100).

It is a super-2 number, since 2×18190000² = 661752200000000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18190000.

It is not an unprimeable number, because it can be changed into a prime (18190001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 169947 + ... + 170053.

Almost surely, 2^18190000 is an apocalyptic number.

18190000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18190000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23533092).

18190000 is an abundant number, since it is smaller than the sum of its proper divisors (28876184).

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

18190000 is a wasteful number, since it uses less digits than its factorization.

18190000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 18190000 is about 4264.9736224272. The cubic root of 18190000 is about 262.9930265564.

Adding to 18190000 its reverse (9181), we get a palindrome (18199181).

The spelling of 18190000 in words is "eighteen million, one hundred ninety thousand".