18172836 has 60 divisors (see below), whose sum is σ = 51836400. Its totient is φ = 5505840.

The previous prime is 18172823. The next prime is 18172837. The reversal of 18172836 is 63827181.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18172836.

It is not an unprimeable number, because it can be changed into a prime (18172837) 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, 1015 + ... + 6113.

It is an arithmetic number, because the mean of its divisors is an integer number (863940).

Almost surely, 2^18172836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18172836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25918200).

18172836 is an abundant number, since it is smaller than the sum of its proper divisors (33663564).

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

18172836 is a wasteful number, since it uses less digits than its factorization.

18172836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5126 (or 5115 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 18172836 is about 4262.9609428190. The cubic root of 18172836 is about 262.9102808563.

The spelling of 18172836 in words is "eighteen million, one hundred seventy-two thousand, eight hundred thirty-six".