21100110199709 has 2 divisors, whose sum is σ = 21100110199710. Its totient is φ = 21100110199708.

The previous prime is 21100110199681. The next prime is 21100110199739. The reversal of 21100110199709 is 90799101100112.

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., 16483778640484 + 4616331559225 = 4060022^2 + 2148565^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100110199709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100110199739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550055099854 + 10550055099855.

It is an arithmetic number, because the mean of its divisors is an integer number (10550055099855).

Almost surely, 2^{21100110199709} is an apocalyptic number.

It is an amenable number.

21100110199709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100110199709 is an equidigital number, since it uses as much as digits as its factorization.

21100110199709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 41.

The spelling of 21100110199709 in words is "twenty-one trillion, one hundred billion, one hundred ten million, one hundred ninety-nine thousand, seven hundred nine".