18990324 has 72 divisors (see below), whose sum is σ = 50417640. Its totient is φ = 6020352.

The previous prime is 18990313. The next prime is 18990353. The reversal of 18990324 is 42309981.

It can be written as a sum of positive squares in 4 ways, for example, as 3920400 + 15069924 = 1980^2 + 3882^2 .

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

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 23 ways as a sum of consecutive naturals, for example, 70462 + ... + 70730.

It is an arithmetic number, because the mean of its divisors is an integer number (700245).

Almost surely, 2^18990324 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 18990324, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25208820).

18990324 is an abundant number, since it is smaller than the sum of its proper divisors (31427316).

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

18990324 is a wasteful number, since it uses less digits than its factorization.

18990324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 364 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 18990324 is about 4357.7888888747. The cubic root of 18990324 is about 266.7948598923.

The spelling of 18990324 in words is "eighteen million, nine hundred ninety thousand, three hundred twenty-four".