21010122121999 has 2 divisors, whose sum is σ = 21010122122000. Its totient is φ = 21010122121998.

The previous prime is 21010122121997. The next prime is 21010122122137. The reversal of 21010122121999 is 99912122101012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21010122121999 - 2¹ = 21010122121997 is a prime.

Together with 21010122121997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010122121991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505061060999 + 10505061061000.

It is an arithmetic number, because the mean of its divisors is an integer number (10505061061000).

Almost surely, 2^{21010122121999} is an apocalyptic number.

21010122121999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010122121999 is an equidigital number, since it uses as much as digits as its factorization.

21010122121999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 40.

The spelling of 21010122121999 in words is "twenty-one trillion, ten billion, one hundred twenty-two million, one hundred twenty-one thousand, nine hundred ninety-nine".