21203240311 has 24 divisors (see below), whose sum is σ = 23470718544. Its totient is φ = 19140000000.

The previous prime is 21203240297. The next prime is 21203240321. The reversal of 21203240311 is 11304230212.

It is a happy number.

It is not a de Polignac number, because 21203240311 - 2²⁵ = 21169685879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203240321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12177901 + ... + 12179641.

It is an arithmetic number, because the mean of its divisors is an integer number (977946606).

Almost surely, 2^21203240311 is an apocalyptic number.

21203240311 is a deficient number, since it is larger than the sum of its proper divisors (2267478233).

21203240311 is a wasteful number, since it uses less digits than its factorization.

21203240311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2415 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21203240311 its reverse (11304230212), we get a palindrome (32507470523).

The spelling of 21203240311 in words is "twenty-one billion, two hundred three million, two hundred forty thousand, three hundred eleven".