21695750099 has 2 divisors, whose sum is σ = 21695750100. Its totient is φ = 21695750098.

The previous prime is 21695750071. The next prime is 21695750101. The reversal of 21695750099 is 99005759612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21695750099 is a prime.

Together with 21695750101, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21695750099.

It is not a weakly prime, because it can be changed into another prime (21695750009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10847875049 + 10847875050.

It is an arithmetic number, because the mean of its divisors is an integer number (10847875050).

Almost surely, 2^21695750099 is an apocalyptic number.

21695750099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21695750099 is an equidigital number, since it uses as much as digits as its factorization.

21695750099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1530900, while the sum is 53.

The spelling of 21695750099 in words is "twenty-one billion, six hundred ninety-five million, seven hundred fifty thousand, ninety-nine".