21021330021 has 8 divisors (see below), whose sum is σ = 28994938080. Its totient is φ = 13530970992.

The previous prime is 21021330013. The next prime is 21021330053. The reversal of 21021330021 is 12003312012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21021330021 - 2³ = 21021330013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021330061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120812155 + ... + 120812328.

It is an arithmetic number, because the mean of its divisors is an integer number (3624367260).

Almost surely, 2^21021330021 is an apocalyptic number.

It is an amenable number.

21021330021 is a deficient number, since it is larger than the sum of its proper divisors (7973608059).

21021330021 is a wasteful number, since it uses less digits than its factorization.

21021330021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241624515.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21021330021 its reverse (12003312012), we get a palindrome (33024642033).

The spelling of 21021330021 in words is "twenty-one billion, twenty-one million, three hundred thirty thousand, twenty-one".