21955746719 has 2 divisors, whose sum is σ = 21955746720. Its totient is φ = 21955746718.

The previous prime is 21955746689. The next prime is 21955746751. The reversal of 21955746719 is 91764755912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21955746719 is a prime.

It is a super-2 number, since 2×21955746719² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21955746119) 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, 10977873359 + 10977873360.

It is an arithmetic number, because the mean of its divisors is an integer number (10977873360).

Almost surely, 2^21955746719 is an apocalyptic number.

21955746719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21955746719 is an equidigital number, since it uses as much as digits as its factorization.

21955746719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4762800, while the sum is 56.

The spelling of 21955746719 in words is "twenty-one billion, nine hundred fifty-five million, seven hundred forty-six thousand, seven hundred nineteen".