21203131311 has 48 divisors (see below), whose sum is σ = 33296508960. Its totient is φ = 12970056960.

The previous prime is 21203131303. The next prime is 21203131331. The reversal of 21203131311 is 11313130212.

21203131311 is a `hidden beast` number, since 21 + 20 + 313 + 1 + 311 = 666.

It is not a de Polignac number, because 21203131311 - 2³ = 21203131303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203131331) 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 47 ways as a sum of consecutive naturals, for example, 389721 + ... + 440781.

It is an arithmetic number, because the mean of its divisors is an integer number (693677270).

Almost surely, 2^21203131311 is an apocalyptic number.

21203131311 is a deficient number, since it is larger than the sum of its proper divisors (12093377649).

21203131311 is a wasteful number, since it uses less digits than its factorization.

21203131311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51176 (or 51173 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21203131311 its reverse (11313130212), we get a palindrome (32516261523).

It can be divided in two parts, 212031 and 31311, that added together give a palindrome (243342).

The spelling of 21203131311 in words is "twenty-one billion, two hundred three million, one hundred thirty-one thousand, three hundred eleven".