21238484881 has 2 divisors, whose sum is σ = 21238484882. Its totient is φ = 21238484880.

The previous prime is 21238484843. The next prime is 21238484887. The reversal of 21238484881 is 18848483212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12547584256 + 8690900625 = 112016^2 + 93225^2 .

It is a cyclic number.

It is not a de Polignac number, because 21238484881 - 2¹⁷ = 21238353809 is a prime.

It is a super-2 number, since 2×21238484881² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21238484887) 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, 10619242440 + 10619242441.

It is an arithmetic number, because the mean of its divisors is an integer number (10619242441).

Almost surely, 2^21238484881 is an apocalyptic number.

It is an amenable number.

21238484881 is a deficient number, since it is larger than the sum of its proper divisors (1).

21238484881 is an equidigital number, since it uses as much as digits as its factorization.

21238484881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 786432, while the sum is 49.

The spelling of 21238484881 in words is "twenty-one billion, two hundred thirty-eight million, four hundred eighty-four thousand, eight hundred eighty-one".