2122212021991 has 4 divisors (see below), whose sum is σ = 2123079295392. Its totient is φ = 2121344748592.

The previous prime is 2122212021971. The next prime is 2122212022027. The reversal of 2122212021991 is 1991202122212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2122212021991 - 2⁷ = 2122212021863 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 (2122212021961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 433633030 + ... + 433637923.

It is an arithmetic number, because the mean of its divisors is an integer number (530769823848).

Almost surely, 2^{2122212021991} is an apocalyptic number.

2122212021991 is a deficient number, since it is larger than the sum of its proper divisors (867273401).

2122212021991 is an equidigital number, since it uses as much as digits as its factorization.

2122212021991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867273400.

The product of its (nonzero) digits is 5184, while the sum is 34.

The spelling of 2122212021991 in words is "two trillion, one hundred twenty-two billion, two hundred twelve million, twenty-one thousand, nine hundred ninety-one".