18819216 has 100 divisors (see below), whose sum is σ = 58710652. Its totient is φ = 5785344.

The previous prime is 18819211. The next prime is 18819239. The reversal of 18819216 is 61291881.

It can be written as a sum of positive squares in 2 ways, for example, as 1679616 + 17139600 = 1296^2 + 4140^2 .

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18819211) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 16290 + ... + 17406.

Almost surely, 2^18819216 is an apocalyptic number.

18819216 is a gapful number since it is divisible by the number (16) 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 18819216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29355326).

18819216 is an abundant number, since it is smaller than the sum of its proper divisors (39891436).

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

18819216 is a wasteful number, since it uses less digits than its factorization.

18819216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1150 (or 1135 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 18819216 is about 4338.1120317484. The cubic root of 18819216 is about 265.9911429768.

The spelling of 18819216 in words is "eighteen million, eight hundred nineteen thousand, two hundred sixteen".