21201220311 has 4 divisors (see below), whose sum is σ = 28268293752. Its totient is φ = 14134146872.

The previous prime is 21201220297. The next prime is 21201220331. The reversal of 21201220311 is 11302210212.

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

It is a cyclic number.

It is not a de Polignac number, because 21201220311 - 2⁵ = 21201220279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201220331) 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, 3533536716 + ... + 3533536721.

It is an arithmetic number, because the mean of its divisors is an integer number (7067073438).

Almost surely, 2^21201220311 is an apocalyptic number.

21201220311 is a deficient number, since it is larger than the sum of its proper divisors (7067073441).

21201220311 is an equidigital number, since it uses as much as digits as its factorization.

21201220311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7067073440.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21201220311 its reverse (11302210212), we get a palindrome (32503430523).

The spelling of 21201220311 in words is "twenty-one billion, two hundred one million, two hundred twenty thousand, three hundred eleven".