23281351021 has 2 divisors, whose sum is σ = 23281351022. Its totient is φ = 23281351020.

The previous prime is 23281351001. The next prime is 23281351031. The reversal of 23281351021 is 12015318232.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20287729225 + 2993621796 = 142435^2 + 54714^2 .

It is a cyclic number.

It is not a de Polignac number, because 23281351021 - 2⁹ = 23281350509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23281351001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11640675510 + 11640675511.

It is an arithmetic number, because the mean of its divisors is an integer number (11640675511).

Almost surely, 2^23281351021 is an apocalyptic number.

It is an amenable number.

23281351021 is a deficient number, since it is larger than the sum of its proper divisors (1).

23281351021 is an equidigital number, since it uses as much as digits as its factorization.

23281351021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

Adding to 23281351021 its reverse (12015318232), we get a palindrome (35296669253).

The spelling of 23281351021 in words is "twenty-three billion, two hundred eighty-one million, three hundred fifty-one thousand, twenty-one".