21200121211099 has 2 divisors, whose sum is σ = 21200121211100. Its totient is φ = 21200121211098.

The previous prime is 21200121211097. The next prime is 21200121211127. The reversal of 21200121211099 is 99011212100212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21200121211099 - 2¹ = 21200121211097 is a prime.

Together with 21200121211097, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21200121211099.

It is not a weakly prime, because it can be changed into another prime (21200121211097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600060605549 + 10600060605550.

It is an arithmetic number, because the mean of its divisors is an integer number (10600060605550).

Almost surely, 2^{21200121211099} is an apocalyptic number.

21200121211099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200121211099 is an equidigital number, since it uses as much as digits as its factorization.

21200121211099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 21200121211099 in words is "twenty-one trillion, two hundred billion, one hundred twenty-one million, two hundred eleven thousand, ninety-nine".