81736522563 has 16 divisors (see below), whose sum is σ = 115474736160. Its totient is φ = 51249217536.

The previous prime is 81736522559. The next prime is 81736522577. The reversal of 81736522563 is 36522563718.

It is a happy number.

It is not a de Polignac number, because 81736522563 - 2² = 81736522559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81736562563) 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 in 15 ways as a sum of consecutive naturals, for example, 496870 + ... + 640587.

It is an arithmetic number, because the mean of its divisors is an integer number (7217171010).

Almost surely, 2^81736522563 is an apocalyptic number.

81736522563 is a deficient number, since it is larger than the sum of its proper divisors (33738213597).

81736522563 is a wasteful number, since it uses less digits than its factorization.

81736522563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138886.

The product of its digits is 1814400, while the sum is 48.

The spelling of 81736522563 in words is "eighty-one billion, seven hundred thirty-six million, five hundred twenty-two thousand, five hundred sixty-three".