21131310331 has 2 divisors, whose sum is σ = 21131310332. Its totient is φ = 21131310330.

The previous prime is 21131310323. The next prime is 21131310337. The reversal of 21131310331 is 13301313112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21131310331 - 2³ = 21131310323 is a prime.

It is a super-2 number, since 2×21131310331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21131310299 and 21131310308.

It is not a weakly prime, because it can be changed into another prime (21131310337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565655165 + 10565655166.

It is an arithmetic number, because the mean of its divisors is an integer number (10565655166).

Almost surely, 2^21131310331 is an apocalyptic number.

21131310331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131310331 is an equidigital number, since it uses as much as digits as its factorization.

21131310331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 21131310331 its reverse (13301313112), we get a palindrome (34432623443).

The spelling of 21131310331 in words is "twenty-one billion, one hundred thirty-one million, three hundred ten thousand, three hundred thirty-one".