21067552109 has 2 divisors, whose sum is σ = 21067552110. Its totient is φ = 21067552108.

The previous prime is 21067552081. The next prime is 21067552111. The reversal of 21067552109 is 90125576012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17931888100 + 3135664009 = 133910^2 + 55997^2 .

It is a cyclic number.

It is not a de Polignac number, because 21067552109 - 2⁸ = 21067551853 is a prime.

Together with 21067552111, 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 (21067552409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533776054 + 10533776055.

It is an arithmetic number, because the mean of its divisors is an integer number (10533776055).

Almost surely, 2^21067552109 is an apocalyptic number.

It is an amenable number.

21067552109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21067552109 is an equidigital number, since it uses as much as digits as its factorization.

21067552109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 38.

The spelling of 21067552109 in words is "twenty-one billion, sixty-seven million, five hundred fifty-two thousand, one hundred nine".