821501340 has 48 divisors (see below), whose sum is σ = 2509315200. Its totient is φ = 199151680.

The previous prime is 821501321. The next prime is 821501341. The reversal of 821501340 is 43105128.

It is a self number, because there is not a number n which added to its sum of digits gives 821501340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821501341) 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, 621690 + ... + 623009.

It is an arithmetic number, because the mean of its divisors is an integer number (52277400).

Almost surely, 2^821501340 is an apocalyptic number.

It is an amenable number.

821501340 is an abundant number, since it is smaller than the sum of its proper divisors (1687813860).

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

821501340 is a wasteful number, since it uses less digits than its factorization.

821501340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244722 (or 1244720 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 821501340 is about 28661.8446719676. The cubic root of 821501340 is about 936.5610495998.

Adding to 821501340 its reverse (43105128), we get a palindrome (864606468).

The spelling of 821501340 in words is "eight hundred twenty-one million, five hundred one thousand, three hundred forty".