21539333 has 2 divisors, whose sum is σ = 21539334. Its totient is φ = 21539332.

The previous prime is 21539321. The next prime is 21539363. The reversal of 21539333 is 33393512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15697444 + 5841889 = 3962^2 + 2417^2 .

It is a cyclic number.

It is not a de Polignac number, because 21539333 - 2¹² = 21535237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21539296 and 21539305.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21539363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10769666 + 10769667.

It is an arithmetic number, because the mean of its divisors is an integer number (10769667).

Almost surely, 2^21539333 is an apocalyptic number.

It is an amenable number.

21539333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21539333 is an equidigital number, since it uses as much as digits as its factorization.

21539333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7290, while the sum is 29.

The square root of 21539333 is about 4641.0486961462. The cubic root of 21539333 is about 278.2343528751.

The spelling of 21539333 in words is "twenty-one million, five hundred thirty-nine thousand, three hundred thirty-three".