21201020311 has 4 divisors (see below), whose sum is σ = 21884924224. Its totient is φ = 20517116400.

The previous prime is 21201020251. The next prime is 21201020317. The reversal of 21201020311 is 11302010212.

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 21201020311 - 2⁹ = 21201019799 is a prime.

It is a super-3 number, since 3×21201020311³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201020291 and 21201020300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201020317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 341951910 + ... + 341951971.

It is an arithmetic number, because the mean of its divisors is an integer number (5471231056).

Almost surely, 2^21201020311 is an apocalyptic number.

21201020311 is a deficient number, since it is larger than the sum of its proper divisors (683903913).

21201020311 is an equidigital number, since it uses as much as digits as its factorization.

21201020311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683903912.

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

Adding to 21201020311 its reverse (11302010212), we get a palindrome (32503030523).

The spelling of 21201020311 in words is "twenty-one billion, two hundred one million, twenty thousand, three hundred eleven".