21716785199 has 2 divisors, whose sum is σ = 21716785200. Its totient is φ = 21716785198.

The previous prime is 21716785183. The next prime is 21716785301. The reversal of 21716785199 is 99158761712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21716785199 - 2⁴ = 21716785183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21716785399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858392599 + 10858392600.

It is an arithmetic number, because the mean of its divisors is an integer number (10858392600).

Almost surely, 2^21716785199 is an apocalyptic number.

21716785199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21716785199 is an equidigital number, since it uses as much as digits as its factorization.

21716785199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1905120, while the sum is 56.

The spelling of 21716785199 in words is "twenty-one billion, seven hundred sixteen million, seven hundred eighty-five thousand, one hundred ninety-nine".