21303030021 has 32 divisors (see below), whose sum is σ = 37015227648. Its totient is φ = 10575774720.

The previous prime is 21303029999. The next prime is 21303030037. The reversal of 21303030021 is 12003030312.

It is not a de Polignac number, because 21303030021 - 2¹⁵ = 21302997253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21303030521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2290450 + ... + 2299731.

It is an arithmetic number, because the mean of its divisors is an integer number (1156725864).

Almost surely, 2^21303030021 is an apocalyptic number.

21303030021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21303030021 is a deficient number, since it is larger than the sum of its proper divisors (15712197627).

21303030021 is a wasteful number, since it uses less digits than its factorization.

21303030021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4590221.

The product of its (nonzero) digits is 108, while the sum is 15.

Adding to 21303030021 its reverse (12003030312), we get a palindrome (33306060333).

The spelling of 21303030021 in words is "twenty-one billion, three hundred three million, thirty thousand, twenty-one".