81606159264 has 96 divisors (see below), whose sum is σ = 251435270016. Its totient is φ = 22685875200.

The previous prime is 81606159233. The next prime is 81606159317. The reversal of 81606159264 is 46295160618.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1616187 + ... + 1665914.

It is an arithmetic number, because the mean of its divisors is an integer number (2619117396).

Almost surely, 2^81606159264 is an apocalyptic number.

81606159264 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81606159264 is an abundant number, since it is smaller than the sum of its proper divisors (169829110752).

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

81606159264 is a wasteful number, since it uses less digits than its factorization.

81606159264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3282158 (or 3282150 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 48.

The spelling of 81606159264 in words is "eighty-one billion, six hundred six million, one hundred fifty-nine thousand, two hundred sixty-four".