21020020333 has 4 divisors (see below), whose sum is σ = 22636944988. Its totient is φ = 19403095680.

The previous prime is 21020020319. The next prime is 21020020337. The reversal of 21020020333 is 33302002012.

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 11290762564 + 9729257769 = 106258^2 + 98637^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020020333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020020337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 808462308 + ... + 808462333.

It is an arithmetic number, because the mean of its divisors is an integer number (5659236247).

Almost surely, 2^21020020333 is an apocalyptic number.

It is an amenable number.

21020020333 is a deficient number, since it is larger than the sum of its proper divisors (1616924655).

21020020333 is a wasteful number, since it uses less digits than its factorization.

21020020333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1616924654.

The product of its (nonzero) digits is 216, while the sum is 16.

Adding to 21020020333 its reverse (33302002012), we get a palindrome (54322022345).

The spelling of 21020020333 in words is "twenty-one billion, twenty million, twenty thousand, three hundred thirty-three".