21719322517 has 8 divisors (see below), whose sum is σ = 22543818752. Its totient is φ = 20902568400.

The previous prime is 21719322511. The next prime is 21719322539. The reversal of 21719322517 is 71522391712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21719322517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21719322517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21719322511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1929813 + ... + 1941034.

It is an arithmetic number, because the mean of its divisors is an integer number (2817977344).

Almost surely, 2^21719322517 is an apocalyptic number.

It is an amenable number.

21719322517 is a deficient number, since it is larger than the sum of its proper divisors (824496235).

21719322517 is a wasteful number, since it uses less digits than its factorization.

21719322517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3871059.

The product of its digits is 52920, while the sum is 40.

The spelling of 21719322517 in words is "twenty-one billion, seven hundred nineteen million, three hundred twenty-two thousand, five hundred seventeen".