21020230100321 has 4 divisors (see below), whose sum is σ = 21034898789892. Its totient is φ = 21005561410752.

The previous prime is 21020230100263. The next prime is 21020230100327. The reversal of 21020230100321 is 12300103202012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7174121187025 + 13846108913296 = 2678455^2 + 3721036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020230100321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21020230100321.

It is not an unprimeable number, because it can be changed into a prime (21020230100327) 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, 7334342636 + ... + 7334345501.

It is an arithmetic number, because the mean of its divisors is an integer number (5258724697473).

Almost surely, 2^{21020230100321} is an apocalyptic number.

It is an amenable number.

21020230100321 is a deficient number, since it is larger than the sum of its proper divisors (14668689571).

21020230100321 is a wasteful number, since it uses less digits than its factorization.

21020230100321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14668689570.

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

Adding to 21020230100321 its reverse (12300103202012), we get a palindrome (33320333302333).

The spelling of 21020230100321 in words is "twenty-one trillion, twenty billion, two hundred thirty million, one hundred thousand, three hundred twenty-one".