21320123201 has 4 divisors (see below), whose sum is σ = 22960132692. Its totient is φ = 19680113712.

The previous prime is 21320123197. The next prime is 21320123203. The reversal of 21320123201 is 10232102312.

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 4724500225 + 16595622976 = 68735^2 + 128824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21320123201 - 2² = 21320123197 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 21320123201.

It is not an unprimeable number, because it can be changed into a prime (21320123203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820004726 + ... + 820004751.

It is an arithmetic number, because the mean of its divisors is an integer number (5740033173).

Almost surely, 2^21320123201 is an apocalyptic number.

It is an amenable number.

21320123201 is a deficient number, since it is larger than the sum of its proper divisors (1640009491).

21320123201 is a wasteful number, since it uses less digits than its factorization.

21320123201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640009490.

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

Adding to 21320123201 its reverse (10232102312), we get a palindrome (31552225513).

The spelling of 21320123201 in words is "twenty-one billion, three hundred twenty million, one hundred twenty-three thousand, two hundred one".