21699388229 has 2 divisors, whose sum is σ = 21699388230. Its totient is φ = 21699388228.

The previous prime is 21699388181. The next prime is 21699388231. The reversal of 21699388229 is 92288399612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21664896100 + 34492129 = 147190^2 + 5873^2 .

It is a cyclic number.

It is not a de Polignac number, because 21699388229 - 2²⁰ = 21698339653 is a prime.

It is a Sophie Germain prime.

Together with 21699388231, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21699388259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10849694114 + 10849694115.

It is an arithmetic number, because the mean of its divisors is an integer number (10849694115).

Almost surely, 2^21699388229 is an apocalyptic number.

It is an amenable number.

21699388229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21699388229 is an equidigital number, since it uses as much as digits as its factorization.

21699388229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6718464, while the sum is 59.

The spelling of 21699388229 in words is "twenty-one billion, six hundred ninety-nine million, three hundred eighty-eight thousand, two hundred twenty-nine".