21722209673 has 2 divisors, whose sum is σ = 21722209674. Its totient is φ = 21722209672.

The previous prime is 21722209669. The next prime is 21722209679. The reversal of 21722209673 is 37690222712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14522178064 + 7200031609 = 120508^2 + 84853^2 .

It is a cyclic number.

It is not a de Polignac number, because 21722209673 - 2² = 21722209669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21722209673.

It is not a weakly prime, because it can be changed into another prime (21722209679) 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, 10861104836 + 10861104837.

It is an arithmetic number, because the mean of its divisors is an integer number (10861104837).

Almost surely, 2^21722209673 is an apocalyptic number.

It is an amenable number.

21722209673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21722209673 is an equidigital number, since it uses as much as digits as its factorization.

21722209673 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 127008, while the sum is 41.

The spelling of 21722209673 in words is "twenty-one billion, seven hundred twenty-two million, two hundred nine thousand, six hundred seventy-three".