21906238033 has 2 divisors, whose sum is σ = 21906238034. Its totient is φ = 21906238032.

The previous prime is 21906238027. The next prime is 21906238073. The reversal of 21906238033 is 33083260912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21794026384 + 112211649 = 147628^2 + 10593^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21906238033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21906237983 and 21906238001.

It is not a weakly prime, because it can be changed into another prime (21906238073) 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, 10953119016 + 10953119017.

It is an arithmetic number, because the mean of its divisors is an integer number (10953119017).

Almost surely, 2^21906238033 is an apocalyptic number.

It is an amenable number.

21906238033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21906238033 is an equidigital number, since it uses as much as digits as its factorization.

21906238033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 37.

Adding to 21906238033 its reverse (33083260912), we get a palindrome (54989498945).

The spelling of 21906238033 in words is "twenty-one billion, nine hundred six million, two hundred thirty-eight thousand, thirty-three".