21222697 has 2 divisors, whose sum is σ = 21222698. Its totient is φ = 21222696.

The previous prime is 21222689. The next prime is 21222739. The reversal of 21222697 is 79622212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10653696 + 10569001 = 3264^2 + 3251^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222697 - 2³ = 21222689 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21262697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611348 + 10611349.

It is an arithmetic number, because the mean of its divisors is an integer number (10611349).

Almost surely, 2^21222697 is an apocalyptic number.

It is an amenable number.

21222697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222697 is an equidigital number, since it uses as much as digits as its factorization.

21222697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 21222697 is about 4606.8098506450. The cubic root of 21222697 is about 276.8642351020.

The spelling of 21222697 in words is "twenty-one million, two hundred twenty-two thousand, six hundred ninety-seven".