21791333 has 2 divisors, whose sum is σ = 21791334. Its totient is φ = 21791332.

The previous prime is 21791311. The next prime is 21791353. The reversal of 21791333 is 33319712.

21791333 is nontrivially palindromic in base 2.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21687649 + 103684 = 4657^2 + 322^2 .

It is a cyclic number.

It is not a de Polignac number, because 21791333 - 2¹⁰ = 21790309 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21791296 and 21791305.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21791353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10895666 + 10895667.

It is an arithmetic number, because the mean of its divisors is an integer number (10895667).

Almost surely, 2^21791333 is an apocalyptic number.

It is an amenable number.

21791333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21791333 is an equidigital number, since it uses as much as digits as its factorization.

21791333 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 29.

The square root of 21791333 is about 4668.1187859779. The cubic root of 21791333 is about 279.3152186381.

The spelling of 21791333 in words is "twenty-one million, seven hundred ninety-one thousand, three hundred thirty-three".