18161500 has 48 divisors (see below), whose sum is σ = 45339840. Its totient is φ = 6225600.

The previous prime is 18161459. The next prime is 18161501. The reversal of 18161500 is 516181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18161501) 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 15 ways as a sum of consecutive naturals, for example, 906 + ... + 6094.

It is an arithmetic number, because the mean of its divisors is an integer number (944580).

Almost surely, 2^18161500 is an apocalyptic number.

18161500 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 18161500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22669920).

18161500 is an abundant number, since it is smaller than the sum of its proper divisors (27178340).

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

18161500 is a wasteful number, since it uses less digits than its factorization.

18161500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5215 (or 5203 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 18161500 is about 4261.6311431188. The cubic root of 18161500 is about 262.8556027117.

Adding to 18161500 its reverse (516181), we get a palindrome (18677681).

The spelling of 18161500 in words is "eighteen million, one hundred sixty-one thousand, five hundred".