21539033 has 2 divisors, whose sum is σ = 21539034. Its totient is φ = 21539032.

The previous prime is 21539029. The next prime is 21539047. The reversal of 21539033 is 33093512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16096144 + 5442889 = 4012^2 + 2333^2 .

It is a cyclic number.

It is not a de Polignac number, because 21539033 - 2² = 21539029 is a prime.

It is a plaindrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 21538993 and 21539011.

It is not a weakly prime, because it can be changed into another prime (21539333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10769516 + 10769517.

It is an arithmetic number, because the mean of its divisors is an integer number (10769517).

Almost surely, 2^21539033 is an apocalyptic number.

It is an amenable number.

21539033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21539033 is an equidigital number, since it uses as much as digits as its factorization.

21539033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2430, while the sum is 26.

The square root of 21539033 is about 4641.0163757522. The cubic root of 21539033 is about 278.2330611190.

The spelling of 21539033 in words is "twenty-one million, five hundred thirty-nine thousand, thirty-three".