21226021567 has 2 divisors, whose sum is σ = 21226021568. Its totient is φ = 21226021566.

The previous prime is 21226021561. The next prime is 21226021571. The reversal of 21226021567 is 76512062212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21226021567 - 2¹¹ = 21226019519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21226021561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613010783 + 10613010784.

It is an arithmetic number, because the mean of its divisors is an integer number (10613010784).

Almost surely, 2^21226021567 is an apocalyptic number.

21226021567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226021567 is an equidigital number, since it uses as much as digits as its factorization.

21226021567 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 34.

Adding to 21226021567 its reverse (76512062212), we get a palindrome (97738083779).

The spelling of 21226021567 in words is "twenty-one billion, two hundred twenty-six million, twenty-one thousand, five hundred sixty-seven".