21226021571 has 2 divisors, whose sum is σ = 21226021572. Its totient is φ = 21226021570.

The previous prime is 21226021567. The next prime is 21226021603. The reversal of 21226021571 is 17512062212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21226021571 - 2² = 21226021567 is a prime.

It is not a weakly prime, because it can be changed into another prime (21226021541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613010785 + 10613010786.

It is an arithmetic number, because the mean of its divisors is an integer number (10613010786).

Almost surely, 2^21226021571 is an apocalyptic number.

21226021571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226021571 is an equidigital number, since it uses as much as digits as its factorization.

21226021571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 29.

Adding to 21226021571 its reverse (17512062212), we get a palindrome (38738083783).

The spelling of 21226021571 in words is "twenty-one billion, two hundred twenty-six million, twenty-one thousand, five hundred seventy-one".