21532535413981 has 2 divisors, whose sum is σ = 21532535413982. Its totient is φ = 21532535413980.

The previous prime is 21532535413979. The next prime is 21532535414009. The reversal of 21532535413981 is 18931453523512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11727652288356 + 9804883125625 = 3424566^2 + 3131275^2 .

It is a cyclic number.

It is not a de Polignac number, because 21532535413981 - 2¹ = 21532535413979 is a prime.

It is a super-2 number, since 2×21532535413981² (a number of 27 digits) contains 22 as substring.

Together with 21532535413979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21532535413951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766267706990 + 10766267706991.

It is an arithmetic number, because the mean of its divisors is an integer number (10766267706991).

Almost surely, 2^{21532535413981} is an apocalyptic number.

It is an amenable number.

21532535413981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21532535413981 is an equidigital number, since it uses as much as digits as its factorization.

21532535413981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888000, while the sum is 52.

The spelling of 21532535413981 in words is "twenty-one trillion, five hundred thirty-two billion, five hundred thirty-five million, four hundred thirteen thousand, nine hundred eighty-one".