2021102019991 has 2 divisors, whose sum is σ = 2021102019992. Its totient is φ = 2021102019990.

The previous prime is 2021102019983. The next prime is 2021102020009. The reversal of 2021102019991 is 1999102011202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2021102019991 - 2³ = 2021102019983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021102019991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021102019931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010551009995 + 1010551009996.

It is an arithmetic number, because the mean of its divisors is an integer number (1010551009996).

Almost surely, 2^{2021102019991} is an apocalyptic number.

2021102019991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021102019991 is an equidigital number, since it uses as much as digits as its factorization.

2021102019991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 37.

The spelling of 2021102019991 in words is "two trillion, twenty-one billion, one hundred two million, nineteen thousand, nine hundred ninety-one".