18312100 has 36 divisors (see below), whose sum is σ = 40036500. Its totient is φ = 7269760.

The previous prime is 18312059. The next prime is 18312101. The reversal of 18312100 is 121381.

It can be written as a sum of positive squares in 6 ways, for example, as 10816 + 18301284 = 104^2 + 4278^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18312101) 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 11 ways as a sum of consecutive naturals, for example, 14286 + ... + 15514.

It is an arithmetic number, because the mean of its divisors is an integer number (1112125).

Almost surely, 2^18312100 is an apocalyptic number.

18312100 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 18312100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20018250).

18312100 is an abundant number, since it is smaller than the sum of its proper divisors (21724400).

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

18312100 is a wasteful number, since it uses less digits than its factorization.

18312100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392 (or 1385 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 18312100 is about 4279.2639554017. The cubic root of 18312100 is about 263.5801598923.

Adding to 18312100 its reverse (121381), we get a palindrome (18433481).

The spelling of 18312100 in words is "eighteen million, three hundred twelve thousand, one hundred".