18943236 has 72 divisors (see below), whose sum is σ = 54624024. Its totient is φ = 5483520.

The previous prime is 18943231. The next prime is 18943241. The reversal of 18943236 is 63234981.

It is an interprime number because it is at equal distance from previous prime (18943231) and next prime (18943241).

It can be written as a sum of positive squares in 4 ways, for example, as 20736 + 18922500 = 144^2 + 4350^2 .

It is a super-3 number, since 3×18943236³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 18943236.

It is not an unprimeable number, because it can be changed into a prime (18943231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6766 + ... + 9146.

It is an arithmetic number, because the mean of its divisors is an integer number (758667).

Almost surely, 2^18943236 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 18943236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27312012).

18943236 is an abundant number, since it is smaller than the sum of its proper divisors (35680788).

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

18943236 is a wasteful number, since it uses less digits than its factorization.

18943236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2421 (or 2416 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 18943236 is about 4352.3827956649. The cubic root of 18943236 is about 266.5741644440.

The spelling of 18943236 in words is "eighteen million, nine hundred forty-three thousand, two hundred thirty-six".