821311340 has 12 divisors (see below), whose sum is σ = 1724753856. Its totient is φ = 328524528.

The previous prime is 821311339. The next prime is 821311343. The reversal of 821311340 is 43113128.

It is not an unprimeable number, because it can be changed into a prime (821311343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20532764 + ... + 20532803.

It is an arithmetic number, because the mean of its divisors is an integer number (143729488).

Almost surely, 2^821311340 is an apocalyptic number.

It is an amenable number.

821311340 is an abundant number, since it is smaller than the sum of its proper divisors (903442516).

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

821311340 is a wasteful number, since it uses less digits than its factorization.

821311340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41065576 (or 41065574 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 821311340 is about 28658.5299692779. The cubic root of 821311340 is about 936.4888402147.

Adding to 821311340 its reverse (43113128), we get a palindrome (864424468).

The spelling of 821311340 in words is "eight hundred twenty-one million, three hundred eleven thousand, three hundred forty".