21822287 has 2 divisors, whose sum is σ = 21822288. Its totient is φ = 21822286.

The previous prime is 21822223. The next prime is 21822293. The reversal of 21822287 is 78222812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21822287 - 2⁶ = 21822223 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 (21822217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10911143 + 10911144.

It is an arithmetic number, because the mean of its divisors is an integer number (10911144).

Almost surely, 2^21822287 is an apocalyptic number.

21822287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21822287 is an equidigital number, since it uses as much as digits as its factorization.

21822287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7168, while the sum is 32.

The square root of 21822287 is about 4671.4330777610. The cubic root of 21822287 is about 279.4474093082.

The spelling of 21822287 in words is "twenty-one million, eight hundred twenty-two thousand, two hundred eighty-seven".