21322571 has 2 divisors, whose sum is σ = 21322572. Its totient is φ = 21322570.

The previous prime is 21322547. The next prime is 21322601. The reversal of 21322571 is 17522312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21322571 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21322871) 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, 10661285 + 10661286.

It is an arithmetic number, because the mean of its divisors is an integer number (10661286).

Almost surely, 2^21322571 is an apocalyptic number.

21322571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21322571 is an equidigital number, since it uses as much as digits as its factorization.

21322571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 21322571 is about 4617.6369497829. The cubic root of 21322571 is about 277.2978632380.

Adding to 21322571 its reverse (17522312), we get a palindrome (38844883).

The spelling of 21322571 in words is "twenty-one million, three hundred twenty-two thousand, five hundred seventy-one".