21030221321 has 4 divisors (see below), whose sum is σ = 21080413200. Its totient is φ = 20980029444.

The previous prime is 21030221309. The next prime is 21030221341. The reversal of 21030221321 is 12312203012.

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 21030221321 - 2¹⁰ = 21030220297 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 21030221321.

It is not an unprimeable number, because it can be changed into a prime (21030221341) 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, 25095311 + ... + 25096148.

It is an arithmetic number, because the mean of its divisors is an integer number (5270103300).

Almost surely, 2^21030221321 is an apocalyptic number.

It is an amenable number.

21030221321 is a deficient number, since it is larger than the sum of its proper divisors (50191879).

21030221321 is an equidigital number, since it uses as much as digits as its factorization.

21030221321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50191878.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21030221321 its reverse (12312203012), we get a palindrome (33342424333).

The spelling of 21030221321 in words is "twenty-one billion, thirty million, two hundred twenty-one thousand, three hundred twenty-one".