821943879285 has 16 divisors (see below), whose sum is σ = 1316116443456. Its totient is φ = 438034656768.

The previous prime is 821943879259. The next prime is 821943879313. The reversal of 821943879285 is 582978349128.

It is not a de Polignac number, because 821943879285 - 2²¹ = 821941782133 is a prime.

It is a super-2 number, since 2×821943879285² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20943004 + ... + 20982213.

It is an arithmetic number, because the mean of its divisors is an integer number (82257277716).

Almost surely, 2^821943879285 is an apocalyptic number.

It is an amenable number.

821943879285 is a deficient number, since it is larger than the sum of its proper divisors (494172564171).

821943879285 is a wasteful number, since it uses less digits than its factorization.

821943879285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41926532.

The product of its digits is 69672960, while the sum is 66.

The spelling of 821943879285 in words is "eight hundred twenty-one billion, nine hundred forty-three million, eight hundred seventy-nine thousand, two hundred eighty-five".