21756336233 has 2 divisors, whose sum is σ = 21756336234. Its totient is φ = 21756336232.

The previous prime is 21756336223. The next prime is 21756336253. The reversal of 21756336233 is 33263365712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11770731049 + 9985605184 = 108493^2 + 99928^2 .

It is a cyclic number.

It is not a de Polignac number, because 21756336233 - 2⁸ = 21756335977 is a prime.

It is not a weakly prime, because it can be changed into another prime (21756336223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10878168116 + 10878168117.

It is an arithmetic number, because the mean of its divisors is an integer number (10878168117).

Almost surely, 2^21756336233 is an apocalyptic number.

It is an amenable number.

21756336233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21756336233 is an equidigital number, since it uses as much as digits as its factorization.

21756336233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 41.

The spelling of 21756336233 in words is "twenty-one billion, seven hundred fifty-six million, three hundred thirty-six thousand, two hundred thirty-three".