21042440033 has 2 divisors, whose sum is σ = 21042440034. Its totient is φ = 21042440032.

The previous prime is 21042440011. The next prime is 21042440051. The reversal of 21042440033 is 33004424012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17776088929 + 3266351104 = 133327^2 + 57152^2 .

It is a cyclic number.

It is not a de Polignac number, because 21042440033 - 2⁶ = 21042439969 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21042439990 and 21042440008.

It is not a weakly prime, because it can be changed into another prime (21042440333) 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, 10521220016 + 10521220017.

It is an arithmetic number, because the mean of its divisors is an integer number (10521220017).

Almost surely, 2^21042440033 is an apocalyptic number.

It is an amenable number.

21042440033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21042440033 is an equidigital number, since it uses as much as digits as its factorization.

21042440033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21042440033 its reverse (33004424012), we get a palindrome (54046864045).

The spelling of 21042440033 in words is "twenty-one billion, forty-two million, four hundred forty thousand, thirty-three".