820391039112221 has 16 divisors (see below), whose sum is σ = 825361073741376. Its totient is φ = 815433760369536.

The previous prime is 820391039112131. The next prime is 820391039112277. The reversal of 820391039112221 is 122211930193028.

It is a cyclic number.

It is not a de Polignac number, because 820391039112221 - 2²² = 820391034917917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820391039112121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 430262255 + ... + 432164771.

It is an arithmetic number, because the mean of its divisors is an integer number (51585067108836).

Almost surely, 2^{820391039112221} is an apocalyptic number.

It is an amenable number.

820391039112221 is a deficient number, since it is larger than the sum of its proper divisors (4970034629155).

820391039112221 is a wasteful number, since it uses less digits than its factorization.

820391039112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905868.

The product of its (nonzero) digits is 93312, while the sum is 44.

The spelling of 820391039112221 in words is "eight hundred twenty trillion, three hundred ninety-one billion, thirty-nine million, one hundred twelve thousand, two hundred twenty-one".