81847166 has 4 divisors (see below), whose sum is σ = 122770752. Its totient is φ = 40923582.

The previous prime is 81847109. The next prime is 81847169. The reversal of 81847166 is 66174818.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81847169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20461790 + ... + 20461793.

It is an arithmetic number, because the mean of its divisors is an integer number (30692688).

Almost surely, 2^81847166 is an apocalyptic number.

81847166 is a deficient number, since it is larger than the sum of its proper divisors (40923586).

81847166 is a wasteful number, since it uses less digits than its factorization.

81847166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40923585.

The product of its digits is 64512, while the sum is 41.

The square root of 81847166 is about 9046.9423563987. The cubic root of 81847166 is about 434.1780683212.

The spelling of 81847166 in words is "eighty-one million, eight hundred forty-seven thousand, one hundred sixty-six".