816822720 has 336 divisors, whose sum is σ = 3317004288. Its totient is φ = 180541440.

The previous prime is 816822719. The next prime is 816822739. The reversal of 816822720 is 27228618.

It is a happy number.

816822720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (336).

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 624307 + ... + 625613.

Almost surely, 2^816822720 is an apocalyptic number.

816822720 is a gapful number since it is divisible by the number (80) 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 816822720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1658502144).

816822720 is an abundant number, since it is smaller than the sum of its proper divisors (2500181568).

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

816822720 is a wasteful number, since it uses less digits than its factorization.

816822720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368 (or 1355 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 816822720 is about 28580.1105666161. The cubic root of 816822720 is about 934.7796939654.

The spelling of 816822720 in words is "eight hundred sixteen million, eight hundred twenty-two thousand, seven hundred twenty".