21200201011991 has 2 divisors, whose sum is σ = 21200201011992. Its totient is φ = 21200201011990.

The previous prime is 21200201011981. The next prime is 21200201012051. The reversal of 21200201011991 is 19911010200212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21200201011991 - 2²⁶ = 21200133903127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21200201011931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600100505995 + 10600100505996.

It is an arithmetic number, because the mean of its divisors is an integer number (10600100505996).

Almost surely, 2^{21200201011991} is an apocalyptic number.

21200201011991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200201011991 is an equidigital number, since it uses as much as digits as its factorization.

21200201011991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 21200201011991 in words is "twenty-one trillion, two hundred billion, two hundred one million, eleven thousand, nine hundred ninety-one".