81137160 has 128 divisors (see below), whose sum is σ = 291312000. Its totient is φ = 19968768.

The previous prime is 81137159. The next prime is 81137179. The reversal of 81137160 is 6173118.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11151 + ... + 16929.

It is an arithmetic number, because the mean of its divisors is an integer number (2275875).

Almost surely, 2^81137160 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 81137160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145656000).

81137160 is an abundant number, since it is smaller than the sum of its proper divisors (210174840).

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

81137160 is a wasteful number, since it uses less digits than its factorization.

81137160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5812 (or 5802 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 81137160 is about 9007.6167769283. The cubic root of 81137160 is about 432.9189542998.

The spelling of 81137160 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred sixty".