21303031231 has 2 divisors, whose sum is σ = 21303031232. Its totient is φ = 21303031230.

The previous prime is 21303031223. The next prime is 21303031261. The reversal of 21303031231 is 13213030312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21303031231 - 2³ = 21303031223 is a prime.

It is a super-2 number, since 2×21303031231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21303031199 and 21303031208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303031261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651515615 + 10651515616.

It is an arithmetic number, because the mean of its divisors is an integer number (10651515616).

Almost surely, 2^21303031231 is an apocalyptic number.

21303031231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303031231 is an equidigital number, since it uses as much as digits as its factorization.

21303031231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21303031231 its reverse (13213030312), we get a palindrome (34516061543).

The spelling of 21303031231 in words is "twenty-one billion, three hundred three million, thirty-one thousand, two hundred thirty-one".