81117473533 has 2 divisors, whose sum is σ = 81117473534. Its totient is φ = 81117473532.

The previous prime is 81117473531. The next prime is 81117473537. The reversal of 81117473533 is 33537471118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65919022009 + 15198451524 = 256747^2 + 123282^2 .

It is a cyclic number.

It is not a de Polignac number, because 81117473533 - 2¹ = 81117473531 is a prime.

Together with 81117473531, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 81117473533.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81117473531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40558736766 + 40558736767.

It is an arithmetic number, because the mean of its divisors is an integer number (40558736767).

Almost surely, 2^81117473533 is an apocalyptic number.

It is an amenable number.

81117473533 is a deficient number, since it is larger than the sum of its proper divisors (1).

81117473533 is an equidigital number, since it uses as much as digits as its factorization.

81117473533 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 43.

The spelling of 81117473533 in words is "eighty-one billion, one hundred seventeen million, four hundred seventy-three thousand, five hundred thirty-three".