21000323231 has 2 divisors, whose sum is σ = 21000323232. Its totient is φ = 21000323230.

The previous prime is 21000323177. The next prime is 21000323237. The reversal of 21000323231 is 13232300012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000323231 - 2³⁰ = 19926581407 is a prime.

It is a super-2 number, since 2×21000323231² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000323237) 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, 10500161615 + 10500161616.

It is an arithmetic number, because the mean of its divisors is an integer number (10500161616).

Almost surely, 2^21000323231 is an apocalyptic number.

21000323231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000323231 is an equidigital number, since it uses as much as digits as its factorization.

21000323231 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 17.

Adding to 21000323231 its reverse (13232300012), we get a palindrome (34232623243).

The spelling of 21000323231 in words is "twenty-one billion, three hundred twenty-three thousand, two hundred thirty-one".