21031220333 has 4 divisors (see below), whose sum is σ = 21045252000. Its totient is φ = 21017188668.

The previous prime is 21031220323. The next prime is 21031220339. The reversal of 21031220333 is 33302213012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21031220333 - 2³⁰ = 19957478509 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 (21031220339) 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, 7013585 + ... + 7016582.

It is an arithmetic number, because the mean of its divisors is an integer number (5261313000).

Almost surely, 2^21031220333 is an apocalyptic number.

It is an amenable number.

21031220333 is a deficient number, since it is larger than the sum of its proper divisors (14031667).

21031220333 is a wasteful number, since it uses less digits than its factorization.

21031220333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14031666.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21031220333 its reverse (33302213012), we get a palindrome (54333433345).

The spelling of 21031220333 in words is "twenty-one billion, thirty-one million, two hundred twenty thousand, three hundred thirty-three".