21202222109 has 2 divisors, whose sum is σ = 21202222110. Its totient is φ = 21202222108.

The previous prime is 21202222099. The next prime is 21202222133. The reversal of 21202222109 is 90122220212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21197904025 + 4318084 = 145595^2 + 2078^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202222109 - 2²⁰ = 21201173533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202222009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601111054 + 10601111055.

It is an arithmetic number, because the mean of its divisors is an integer number (10601111055).

Almost surely, 2^21202222109 is an apocalyptic number.

It is an amenable number.

21202222109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202222109 is an equidigital number, since it uses as much as digits as its factorization.

21202222109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The spelling of 21202222109 in words is "twenty-one billion, two hundred two million, two hundred twenty-two thousand, one hundred nine".