21226021541 has 2 divisors, whose sum is σ = 21226021542. Its totient is φ = 21226021540.

The previous prime is 21226021507. The next prime is 21226021561. The reversal of 21226021541 is 14512062212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20100150625 + 1125870916 = 141775^2 + 33554^2 .

It is a cyclic number.

It is not a de Polignac number, because 21226021541 - 2¹⁸ = 21225759397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21226021541.

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 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, 10613010770 + 10613010771.

It is an arithmetic number, because the mean of its divisors is an integer number (10613010771).

Almost surely, 2^21226021541 is an apocalyptic number.

It is an amenable number.

21226021541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226021541 is an equidigital number, since it uses as much as digits as its factorization.

21226021541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 21226021541 its reverse (14512062212), we get a palindrome (35738083753).

The spelling of 21226021541 in words is "twenty-one billion, two hundred twenty-six million, twenty-one thousand, five hundred forty-one".