18213132 has 48 divisors (see below), whose sum is σ = 49496832. Its totient is φ = 5104320.

The previous prime is 18213119. The next prime is 18213149. The reversal of 18213132 is 23131281.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 18213099 and 18213108.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2407 + ... + 6497.

It is an arithmetic number, because the mean of its divisors is an integer number (1031184).

Almost surely, 2^18213132 is an apocalyptic number.

18213132 is a gapful number since it is divisible by the number (12) 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 18213132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24748416).

18213132 is an abundant number, since it is smaller than the sum of its proper divisors (31283700).

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

18213132 is a wasteful number, since it uses less digits than its factorization.

18213132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4158 (or 4156 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

The square root of 18213132 is about 4267.6846181507. The cubic root of 18213132 is about 263.1044610023.

The spelling of 18213132 in words is "eighteen million, two hundred thirteen thousand, one hundred thirty-two".