81866110 has 8 divisors (see below), whose sum is σ = 147359016. Its totient is φ = 32746440.

The previous prime is 81866107. The next prime is 81866123. The reversal of 81866110 is 1166818.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4093296 + ... + 4093315.

It is an arithmetic number, because the mean of its divisors is an integer number (18419877).

Almost surely, 2^81866110 is an apocalyptic number.

81866110 is a deficient number, since it is larger than the sum of its proper divisors (65492906).

81866110 is a wasteful number, since it uses less digits than its factorization.

81866110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8186618.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 81866110 is about 9047.9892793924. The cubic root of 81866110 is about 434.2115634122.

The spelling of 81866110 in words is "eighty-one million, eight hundred sixty-six thousand, one hundred ten".