220021011991 has 12 divisors (see below), whose sum is σ = 242129638800. Its totient is φ = 199780607840.

The previous prime is 220021011989. The next prime is 220021012009. The reversal of 220021011991 is 199110120022.

220021011991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 220021011991 - 2¹ = 220021011989 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 (220021011941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 982126 + ... + 1185163.

It is an arithmetic number, because the mean of its divisors is an integer number (20177469900).

Almost surely, 2^220021011991 is an apocalyptic number.

220021011991 is a deficient number, since it is larger than the sum of its proper divisors (22108626809).

220021011991 is a wasteful number, since it uses less digits than its factorization.

220021011991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168150 (or 2168139 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 28.

The spelling of 220021011991 in words is "two hundred twenty billion, twenty-one million, eleven thousand, nine hundred ninety-one".