81647166 has 8 divisors (see below), whose sum is σ = 163294344. Its totient is φ = 27215720.

The previous prime is 81647143. The next prime is 81647207. The reversal of 81647166 is 66174618.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

81647166 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6803925 + ... + 6803936.

It is an arithmetic number, because the mean of its divisors is an integer number (20411793).

Almost surely, 2^81647166 is an apocalyptic number.

81647166 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81647166 is a wasteful number, since it uses less digits than its factorization.

81647166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13607866.

The product of its digits is 48384, while the sum is 39.

The square root of 81647166 is about 9035.8821373455. The cubic root of 81647166 is about 433.8241304311.

The spelling of 81647166 in words is "eighty-one million, six hundred forty-seven thousand, one hundred sixty-six".