21422717 has 2 divisors, whose sum is σ = 21422718. Its totient is φ = 21422716.

The previous prime is 21422711. The next prime is 21422743. The reversal of 21422717 is 71722412.

It is an a-pointer prime, because the next prime (21422743) can be obtained adding 21422717 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20693401 + 729316 = 4549^2 + 854^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422717 - 2⁸ = 21422461 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711358 + 10711359.

It is an arithmetic number, because the mean of its divisors is an integer number (10711359).

Almost surely, 2^21422717 is an apocalyptic number.

It is an amenable number.

21422717 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422717 is an equidigital number, since it uses as much as digits as its factorization.

21422717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1568, while the sum is 26.

The square root of 21422717 is about 4628.4681051078. The cubic root of 21422717 is about 277.7313148539.

The spelling of 21422717 in words is "twenty-one million, four hundred twenty-two thousand, seven hundred seventeen".