813447440 has 160 divisors (see below), whose sum is σ = 2195859456. Its totient is φ = 277770240.

The previous prime is 813447407. The next prime is 813447461. The reversal of 813447440 is 44744318.

It is a Cunningham number, because it is equal to 28521²-1.

It is a self number, because there is not a number n which added to its sum of digits gives 813447440.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 740972 + ... + 742068.

Almost surely, 2^813447440 is an apocalyptic number.

813447440 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 813447440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1097929728).

813447440 is an abundant number, since it is smaller than the sum of its proper divisors (1382412016).

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

813447440 is a wasteful number, since it uses less digits than its factorization.

813447440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1177 (or 1171 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 35.

The square root of 813447440 is about 28520.9999824691. Note that the first 4 decimals coincide. The cubic root of 813447440 is about 933.4903488671.

The spelling of 813447440 in words is "eight hundred thirteen million, four hundred forty-seven thousand, four hundred forty".