823801440 has 384 divisors, whose sum is σ = 3344302080. Its totient is φ = 165427200.

The previous prime is 823801417. The next prime is 823801457. The reversal of 823801440 is 44108328.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 823801398 and 823801407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1145401 + ... + 1146119.

It is an arithmetic number, because the mean of its divisors is an integer number (8709120).

Almost surely, 2^823801440 is an apocalyptic number.

823801440 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 823801440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1672151040).

823801440 is an abundant number, since it is smaller than the sum of its proper divisors (2520500640).

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

823801440 is a wasteful number, since it uses less digits than its factorization.

823801440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 823801440 is about 28701.9413977522. The cubic root of 823801440 is about 937.4343193097.

Adding to 823801440 its reverse (44108328), we get a palindrome (867909768).

The spelling of 823801440 in words is "eight hundred twenty-three million, eight hundred one thousand, four hundred forty".