821085642240 has 80 divisors (see below), whose sum is σ = 2624908187088. Its totient is φ = 218956169216.

The previous prime is 821085642163. The next prime is 821085642359. The reversal of 821085642240 is 42246580128.

It is a tau number, because it is divible by the number of its divisors (80).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 821085642192 and 821085642201.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 53448417 + ... + 53463776.

Almost surely, 2^821085642240 is an apocalyptic number.

821085642240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

821085642240 is an abundant number, since it is smaller than the sum of its proper divisors (1803822544848).

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

821085642240 is a wasteful number, since it uses less digits than its factorization.

821085642240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106912219 (or 106912203 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 42.

The spelling of 821085642240 in words is "eight hundred twenty-one billion, eighty-five million, six hundred forty-two thousand, two hundred forty".