21060533 has 4 divisors (see below), whose sum is σ = 22680588. Its totient is φ = 19440480.

The previous prime is 21060509. The next prime is 21060539. The reversal of 21060533 is 33506012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2380849 + 18679684 = 1543^2 + 4322^2 .

It is a cyclic number.

It is not a de Polignac number, because 21060533 - 2⁶ = 21060469 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 810008 + ... + 810033.

It is an arithmetic number, because the mean of its divisors is an integer number (5670147).

Almost surely, 2^21060533 is an apocalyptic number.

It is an amenable number.

21060533 is a deficient number, since it is larger than the sum of its proper divisors (1620055).

21060533 is a wasteful number, since it uses less digits than its factorization.

21060533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620054.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 21060533 is about 4589.1756340328. The cubic root of 21060533 is about 276.1572521578.

Adding to 21060533 its reverse (33506012), we get a palindrome (54566545).

The spelling of 21060533 in words is "twenty-one million, sixty thousand, five hundred thirty-three".