21142405481 has 2 divisors, whose sum is σ = 21142405482. Its totient is φ = 21142405480.

The previous prime is 21142405397. The next prime is 21142405513. The reversal of 21142405481 is 18450424112.

It is an a-pointer prime, because the next prime (21142405513) can be obtained adding 21142405481 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19482576400 + 1659829081 = 139580^2 + 40741^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142405481 - 2²² = 21138211177 is a prime.

It is a super-2 number, since 2×21142405481² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21142402481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571202740 + 10571202741.

It is an arithmetic number, because the mean of its divisors is an integer number (10571202741).

Almost surely, 2^21142405481 is an apocalyptic number.

It is an amenable number.

21142405481 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142405481 is an equidigital number, since it uses as much as digits as its factorization.

21142405481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10240, while the sum is 32.

Adding to 21142405481 its reverse (18450424112), we get a palindrome (39592829593).

The spelling of 21142405481 in words is "twenty-one billion, one hundred forty-two million, four hundred five thousand, four hundred eighty-one".