21201311213 has 4 divisors (see below), whose sum is σ = 21932390940. Its totient is φ = 20470231488.

The previous prime is 21201311203. The next prime is 21201311221. The reversal of 21201311213 is 31211310212.

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 7499906404 + 13701404809 = 86602^2 + 117053^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201311213 - 2⁸ = 21201310957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201311191 and 21201311200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201311203) 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, 365539820 + ... + 365539877.

It is an arithmetic number, because the mean of its divisors is an integer number (5483097735).

Almost surely, 2^21201311213 is an apocalyptic number.

It is an amenable number.

21201311213 is a deficient number, since it is larger than the sum of its proper divisors (731079727).

21201311213 is an equidigital number, since it uses as much as digits as its factorization.

21201311213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731079726.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21201311213 its reverse (31211310212), we get a palindrome (52412621425).

The spelling of 21201311213 in words is "twenty-one billion, two hundred one million, three hundred eleven thousand, two hundred thirteen".