21103212331 has 2 divisors, whose sum is σ = 21103212332. Its totient is φ = 21103212330.

The previous prime is 21103212289. The next prime is 21103212341. The reversal of 21103212331 is 13321230112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21103212331 - 2⁷ = 21103212203 is a prime.

It is a super-2 number, since 2×21103212331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21103212299 and 21103212308.

It is not a weakly prime, because it can be changed into another prime (21103212341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551606165 + 10551606166.

It is an arithmetic number, because the mean of its divisors is an integer number (10551606166).

Almost surely, 2^21103212331 is an apocalyptic number.

21103212331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103212331 is an equidigital number, since it uses as much as digits as its factorization.

21103212331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21103212331 its reverse (13321230112), we get a palindrome (34424442443).

The spelling of 21103212331 in words is "twenty-one billion, one hundred three million, two hundred twelve thousand, three hundred thirty-one".