21265731433 has 2 divisors, whose sum is σ = 21265731434. Its totient is φ = 21265731432.

The previous prime is 21265731413. The next prime is 21265731439. The reversal of 21265731433 is 33413756212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19080449424 + 2185282009 = 138132^2 + 46747^2 .

It is a cyclic number.

It is not a de Polignac number, because 21265731433 - 2¹⁷ = 21265600361 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21265731392 and 21265731401.

It is not a weakly prime, because it can be changed into another prime (21265731439) 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, 10632865716 + 10632865717.

It is an arithmetic number, because the mean of its divisors is an integer number (10632865717).

Almost surely, 2^21265731433 is an apocalyptic number.

It is an amenable number.

21265731433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265731433 is an equidigital number, since it uses as much as digits as its factorization.

21265731433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 37.

The spelling of 21265731433 in words is "twenty-one billion, two hundred sixty-five million, seven hundred thirty-one thousand, four hundred thirty-three".