21422056109 has 2 divisors, whose sum is σ = 21422056110. Its totient is φ = 21422056108.

The previous prime is 21422056009. The next prime is 21422056111. The reversal of 21422056109 is 90165022412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14976374884 + 6445681225 = 122378^2 + 80285^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422056109 - 2¹² = 21422052013 is a prime.

Together with 21422056111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422056129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711028054 + 10711028055.

It is an arithmetic number, because the mean of its divisors is an integer number (10711028055).

Almost surely, 2^21422056109 is an apocalyptic number.

It is an amenable number.

21422056109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422056109 is an equidigital number, since it uses as much as digits as its factorization.

21422056109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 21422056109 in words is "twenty-one billion, four hundred twenty-two million, fifty-six thousand, one hundred nine".