823616640 has 512 divisors, whose sum is σ = 3642624000. Its totient is φ = 170864640.

The previous prime is 823616603. The next prime is 823616671. The reversal of 823616640 is 46616328.

823616640 is a `hidden beast` number, since 8 + 2 + 3 + 6 + 1 + 6 + 640 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 823616595 and 823616604.

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 63 ways as a sum of consecutive naturals, for example, 1330251 + ... + 1330869.

It is an arithmetic number, because the mean of its divisors is an integer number (7114500).

Almost surely, 2^823616640 is an apocalyptic number.

823616640 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 823616640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1821312000).

823616640 is an abundant number, since it is smaller than the sum of its proper divisors (2819007360).

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

823616640 is a wasteful number, since it uses less digits than its factorization.

823616640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 823616640 is about 28698.7219227616. The cubic root of 823616640 is about 937.3642171348.

The spelling of 823616640 in words is "eight hundred twenty-three million, six hundred sixteen thousand, six hundred forty".