81137166 has 16 divisors (see below), whose sum is σ = 177026688. Its totient is φ = 24587000.

The previous prime is 81137159. The next prime is 81137179. The reversal of 81137166 is 66173118.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

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, 614610 + ... + 614741.

It is an arithmetic number, because the mean of its divisors is an integer number (11064168).

Almost surely, 2^81137166 is an apocalyptic number.

81137166 is an abundant number, since it is smaller than the sum of its proper divisors (95889522).

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

81137166 is a wasteful number, since it uses less digits than its factorization.

81137166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229367.

The product of its digits is 6048, while the sum is 33.

The square root of 81137166 is about 9007.6171099798. The cubic root of 81137166 is about 432.9189649711.

The spelling of 81137166 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred sixty-six".