21201173533 has 2 divisors, whose sum is σ = 21201173534. Its totient is φ = 21201173532.

The previous prime is 21201173527. The next prime is 21201173561. The reversal of 21201173533 is 33537110212.

It is an a-pointer prime, because the next prime (21201173561) can be obtained adding 21201173533 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21090881529 + 110292004 = 145227^2 + 10502^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201173533 - 2¹⁷ = 21201042461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201173033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600586766 + 10600586767.

It is an arithmetic number, because the mean of its divisors is an integer number (10600586767).

Almost surely, 2^21201173533 is an apocalyptic number.

It is an amenable number.

21201173533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201173533 is an equidigital number, since it uses as much as digits as its factorization.

21201173533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 28.

Adding to 21201173533 its reverse (33537110212), we get a palindrome (54738283745).

The spelling of 21201173533 in words is "twenty-one billion, two hundred one million, one hundred seventy-three thousand, five hundred thirty-three".