21101107309 has 2 divisors, whose sum is σ = 21101107310. Its totient is φ = 21101107308.

The previous prime is 21101107303. The next prime is 21101107351. The reversal of 21101107309 is 90370110112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20969936100 + 131171209 = 144810^2 + 11453^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101107309 - 2⁹ = 21101106797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101107303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550553654 + 10550553655.

It is an arithmetic number, because the mean of its divisors is an integer number (10550553655).

Almost surely, 2^21101107309 is an apocalyptic number.

It is an amenable number.

21101107309 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101107309 is an equidigital number, since it uses as much as digits as its factorization.

21101107309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 25.

The spelling of 21101107309 in words is "twenty-one billion, one hundred one million, one hundred seven thousand, three hundred nine".