2020121209991 has 2 divisors, whose sum is σ = 2020121209992. Its totient is φ = 2020121209990.

The previous prime is 2020121209961. The next prime is 2020121210071. The reversal of 2020121209991 is 1999021210202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2020121209991 - 2²² = 2020117015687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2020121209921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010060604995 + 1010060604996.

It is an arithmetic number, because the mean of its divisors is an integer number (1010060604996).

Almost surely, 2^{2020121209991} is an apocalyptic number.

2020121209991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2020121209991 is an equidigital number, since it uses as much as digits as its factorization.

2020121209991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 2020121209991 in words is "two trillion, twenty billion, one hundred twenty-one million, two hundred nine thousand, nine hundred ninety-one".