81466861915 has 16 divisors (see below), whose sum is σ = 101227690080. Its totient is φ = 62866137600.

The previous prime is 81466861907. The next prime is 81466861919. The reversal of 81466861915 is 51916866418.

It is not a de Polignac number, because 81466861915 - 2³ = 81466861907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81466861919) 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 in 15 ways as a sum of consecutive naturals, for example, 114894 + ... + 419683.

It is an arithmetic number, because the mean of its divisors is an integer number (6326730630).

Almost surely, 2^81466861915 is an apocalyptic number.

81466861915 is a deficient number, since it is larger than the sum of its proper divisors (19760828165).

81466861915 is a wasteful number, since it uses less digits than its factorization.

81466861915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535662.

The product of its digits is 2488320, while the sum is 55.

The spelling of 81466861915 in words is "eighty-one billion, four hundred sixty-six million, eight hundred sixty-one thousand, nine hundred fifteen".