19722917 has 2 divisors, whose sum is σ = 19722918. Its totient is φ = 19722916.

The previous prime is 19722881. The next prime is 19722919. The reversal of 19722917 is 71922791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18653761 + 1069156 = 4319^2 + 1034^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19722917 is a prime.

Together with 19722919, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19722919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9861458 + 9861459.

It is an arithmetic number, because the mean of its divisors is an integer number (9861459).

Almost surely, 2^19722917 is an apocalyptic number.

It is an amenable number.

19722917 is a deficient number, since it is larger than the sum of its proper divisors (1).

19722917 is an equidigital number, since it uses as much as digits as its factorization.

19722917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15876, while the sum is 38.

The square root of 19722917 is about 4441.0490877719. The cubic root of 19722917 is about 270.1823961891.

The spelling of 19722917 in words is "nineteen million, seven hundred twenty-two thousand, nine hundred seventeen".