813133440 has 576 divisors, whose sum is σ = 3392120160. Its totient is φ = 178827264.

The previous prime is 813133439. The next prime is 813133471. The reversal of 813133440 is 44331318.

813133440 is a `hidden beast` number, since 8 + 1 + 313 + 344 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×813133440² = 1322371982492467200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 12136287 + ... + 12136353.

Almost surely, 2^813133440 is an apocalyptic number.

813133440 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 813133440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1696060080).

813133440 is an abundant number, since it is smaller than the sum of its proper divisors (2578986720).

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

813133440 is a wasteful number, since it uses less digits than its factorization.

813133440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 813133440 is about 28515.4947353189. The cubic root of 813133440 is about 933.3702207643.

Adding to 813133440 its reverse (44331318), we get a palindrome (857464758).

The spelling of 813133440 in words is "eight hundred thirteen million, one hundred thirty-three thousand, four hundred forty".