2101021100209 has 2 divisors, whose sum is σ = 2101021100210. Its totient is φ = 2101021100208.

The previous prime is 2101021100207. The next prime is 2101021100281. The reversal of 2101021100209 is 9020011201012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2044122153984 + 56898946225 = 1429728^2 + 238535^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101021100209 - 2¹ = 2101021100207 is a prime.

Together with 2101021100207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2101021100207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050510550104 + 1050510550105.

It is an arithmetic number, because the mean of its divisors is an integer number (1050510550105).

Almost surely, 2^{2101021100209} is an apocalyptic number.

It is an amenable number.

2101021100209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101021100209 is an equidigital number, since it uses as much as digits as its factorization.

2101021100209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 2101021100209 in words is "two trillion, one hundred one billion, twenty-one million, one hundred thousand, two hundred nine".