21001324231 has 2 divisors, whose sum is σ = 21001324232. Its totient is φ = 21001324230.

The previous prime is 21001324189. The next prime is 21001324237. The reversal of 21001324231 is 13242310012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21001324231 - 2⁷ = 21001324103 is a prime.

It is a super-2 number, since 2×21001324231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21001324199 and 21001324208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001324237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500662115 + 10500662116.

It is an arithmetic number, because the mean of its divisors is an integer number (10500662116).

Almost surely, 2^21001324231 is an apocalyptic number.

21001324231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001324231 is an equidigital number, since it uses as much as digits as its factorization.

21001324231 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21001324231 its reverse (13242310012), we get a palindrome (34243634243).

The spelling of 21001324231 in words is "twenty-one billion, one million, three hundred twenty-four thousand, two hundred thirty-one".