18190100 has 36 divisors (see below), whose sum is σ = 39885468. Its totient is φ = 7200000.

The previous prime is 18190093. The next prime is 18190103. The reversal of 18190100 is 109181.

It can be written as a sum of positive squares in 6 ways, for example, as 59536 + 18130564 = 244^2 + 4258^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18190103) 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 11 ways as a sum of consecutive naturals, for example, 9200 + ... + 11000.

Almost surely, 2^18190100 is an apocalyptic number.

18190100 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 18190100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19942734).

18190100 is an abundant number, since it is smaller than the sum of its proper divisors (21695368).

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

18190100 is a wasteful number, since it uses less digits than its factorization.

18190100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1916 (or 1909 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 18190100 is about 4264.9853458130. The cubic root of 18190100 is about 262.9935084925.

Adding to 18190100 its reverse (109181), we get a palindrome (18299281).

The spelling of 18190100 in words is "eighteen million, one hundred ninety thousand, one hundred".