81137168 has 40 divisors (see below), whose sum is σ = 185464320. Its totient is φ = 33649920.

The previous prime is 81137159. The next prime is 81137179. The reversal of 81137168 is 86173118.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8213 + ... + 15156.

It is an arithmetic number, because the mean of its divisors is an integer number (4636608).

Almost surely, 2^81137168 is an apocalyptic number.

It is an amenable number.

81137168 is an abundant number, since it is smaller than the sum of its proper divisors (104327152).

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

81137168 is a wasteful number, since it uses less digits than its factorization.

81137168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23415 (or 23409 counting only the distinct ones).

The product of its digits is 8064, while the sum is 35.

The square root of 81137168 is about 9007.6172209969. The cubic root of 81137168 is about 432.9189685282.

The spelling of 81137168 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred sixty-eight".