21201230321 has 8 divisors (see below), whose sum is σ = 21229701480. Its totient is φ = 21172780288.

The previous prime is 21201230311. The next prime is 21201230327. The reversal of 21201230321 is 12303210212.

It can be written as a sum of positive squares in 4 ways, for example, as 4024506721 + 17176723600 = 63439^2 + 131060^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21201230321 - 2²² = 21197036017 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 21201230321.

It is not an unprimeable number, because it can be changed into a prime (21201230327) 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, 3083075 + ... + 3089943.

It is an arithmetic number, because the mean of its divisors is an integer number (2653712685).

Almost surely, 2^21201230321 is an apocalyptic number.

It is an amenable number.

21201230321 is a deficient number, since it is larger than the sum of its proper divisors (28471159).

21201230321 is a wasteful number, since it uses less digits than its factorization.

21201230321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10563.

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

Adding to 21201230321 its reverse (12303210212), we get a palindrome (33504440533).

The spelling of 21201230321 in words is "twenty-one billion, two hundred one million, two hundred thirty thousand, three hundred twenty-one".