81167708160 has 1872 divisors, whose sum is σ = 384565484160. Its totient is φ = 15606743040.

The previous prime is 81167708137. The next prime is 81167708161. The reversal of 81167708160 is 6180776118.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81167708161) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1887621099 + ... + 1887621141.

It is an arithmetic number, because the mean of its divisors is an integer number (205430280).

Almost surely, 2^81167708160 is an apocalyptic number.

81167708160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81167708160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192282742080).

81167708160 is an abundant number, since it is smaller than the sum of its proper divisors (303397776000).

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

81167708160 is a wasteful number, since it uses less digits than its factorization.

81167708160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The spelling of 81167708160 in words is "eighty-one billion, one hundred sixty-seven million, seven hundred eight thousand, one hundred sixty".