818221824 has 216 divisors, whose sum is σ = 2797500160. Its totient is φ = 233653248.

The previous prime is 818221823. The next prime is 818221829. The reversal of 818221824 is 428122818.

It is a tau number, because it is divible by the number of its divisors (216).

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 (818221823) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 434517 + ... + 436395.

Almost surely, 2^818221824 is an apocalyptic number.

818221824 is a gapful number since it is divisible by the number (84) 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 818221824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1398750080).

818221824 is an abundant number, since it is smaller than the sum of its proper divisors (1979278336).

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

818221824 is an equidigital number, since it uses as much as digits as its factorization.

818221824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1917 (or 1891 counting only the distinct ones).

The product of its digits is 16384, while the sum is 36.

The square root of 818221824 is about 28604.5769764211. The cubic root of 818221824 is about 935.3131055052.

The spelling of 818221824 in words is "eight hundred eighteen million, two hundred twenty-one thousand, eight hundred twenty-four".