823664944640 has 160 divisors (see below), whose sum is σ = 2134994289120. Its totient is φ = 303689170944.

The previous prime is 823664944631. The next prime is 823664944643. The reversal of 823664944640 is 46449466328.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823664944643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1570844 + ... + 2028516.

It is an arithmetic number, because the mean of its divisors is an integer number (13343714307).

Almost surely, 2^823664944640 is an apocalyptic number.

823664944640 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 823664944640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067497144560).

823664944640 is an abundant number, since it is smaller than the sum of its proper divisors (1311329344480).

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

823664944640 is a wasteful number, since it uses less digits than its factorization.

823664944640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457752 (or 457736 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 56.

The spelling of 823664944640 in words is "eight hundred twenty-three billion, six hundred sixty-four million, nine hundred forty-four thousand, six hundred forty".