81646118 has 8 divisors (see below), whose sum is σ = 123085200. Its totient is φ = 40617720.

The previous prime is 81646111. The next prime is 81646127. The reversal of 81646118 is 81164618.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81646111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102173 + ... + 102968.

It is an arithmetic number, because the mean of its divisors is an integer number (15385650).

Almost surely, 2^81646118 is an apocalyptic number.

81646118 is a deficient number, since it is larger than the sum of its proper divisors (41439082).

81646118 is a wasteful number, since it uses less digits than its factorization.

81646118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205342.

The product of its digits is 9216, while the sum is 35.

The square root of 81646118 is about 9035.8241461418. The cubic root of 81646118 is about 433.8222742751.

The spelling of 81646118 in words is "eighty-one million, six hundred forty-six thousand, one hundred eighteen".