21064033 has 4 divisors (see below), whose sum is σ = 21084948. Its totient is φ = 21043120.

The previous prime is 21064031. The next prime is 21064039. The reversal of 21064033 is 33046012.

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 8340544 + 12723489 = 2888^2 + 3567^2 .

It is a cyclic number.

It is not a de Polignac number, because 21064033 - 2¹ = 21064031 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21064033.

It is not an unprimeable number, because it can be changed into a prime (21064031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8866 + ... + 10987.

It is an arithmetic number, because the mean of its divisors is an integer number (5271237).

Almost surely, 2^21064033 is an apocalyptic number.

It is an amenable number.

21064033 is a deficient number, since it is larger than the sum of its proper divisors (20915).

21064033 is a wasteful number, since it uses less digits than its factorization.

21064033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20914.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21064033 is about 4589.5569502949. The cubic root of 21064033 is about 276.1725492833.

The spelling of 21064033 in words is "twenty-one million, sixty-four thousand, thirty-three".