81505450518 has 32 divisors (see below), whose sum is σ = 167434260576. Its totient is φ = 26431411968.

The previous prime is 81505450493. The next prime is 81505450519.

81505450518 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 81505450518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81505450519) 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 in 15 ways as a sum of consecutive naturals, for example, 3668130 + ... + 3690282.

It is an arithmetic number, because the mean of its divisors is an integer number (5232320643).

Almost surely, 2^81505450518 is an apocalyptic number.

81505450518 is an abundant number, since it is smaller than the sum of its proper divisors (85928810058).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81505450518 is a wasteful number, since it uses less digits than its factorization.

81505450518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38768.

The product of its (nonzero) digits is 160000, while the sum is 42.

The spelling of 81505450518 in words is "eighty-one billion, five hundred five million, four hundred fifty thousand, five hundred eighteen".