81278320176 has 180 divisors, whose sum is σ = 236515393296. Its totient is φ = 26054403840.

The previous prime is 81278320159. The next prime is 81278320177. The reversal of 81278320176 is 67102387218.

It is not an unprimeable number, because it can be changed into a prime (81278320177) 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 35 ways as a sum of consecutive naturals, for example, 23108370 + ... + 23111886.

Almost surely, 2^81278320176 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81278320176, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118257696648).

81278320176 is an abundant number, since it is smaller than the sum of its proper divisors (155237073120).

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

81278320176 is a wasteful number, since it uses less digits than its factorization.

81278320176 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3760 (or 3720 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The spelling of 81278320176 in words is "eighty-one billion, two hundred seventy-eight million, three hundred twenty thousand, one hundred seventy-six".