21011320201 has 4 divisors (see below), whose sum is σ = 21031661332. Its totient is φ = 20990979072.

The previous prime is 21011320133. The next prime is 21011320217. The reversal of 21011320201 is 10202311012.

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 14494956025 + 6516364176 = 120395^2 + 80724^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011320201 - 2²¹ = 21009223049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011320261) 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, 10169016 + ... + 10171081.

It is an arithmetic number, because the mean of its divisors is an integer number (5257915333).

Almost surely, 2^21011320201 is an apocalyptic number.

It is an amenable number.

21011320201 is a deficient number, since it is larger than the sum of its proper divisors (20341131).

21011320201 is a wasteful number, since it uses less digits than its factorization.

21011320201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20341130.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21011320201 its reverse (10202311012), we get a palindrome (31213631213).

The spelling of 21011320201 in words is "twenty-one billion, eleven million, three hundred twenty thousand, two hundred one".