81107687 has 8 divisors (see below), whose sum is σ = 84283392. Its totient is φ = 77967000.

The previous prime is 81107681. The next prime is 81107701. The reversal of 81107687 is 78670118.

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

It is a cyclic number.

It is not a de Polignac number, because 81107687 - 2¹⁴ = 81091303 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81107687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81107681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3983 + ... + 13344.

It is an arithmetic number, because the mean of its divisors is an integer number (10535424).

Almost surely, 2^81107687 is an apocalyptic number.

81107687 is a deficient number, since it is larger than the sum of its proper divisors (3175705).

81107687 is a wasteful number, since it uses less digits than its factorization.

81107687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17509.

The product of its (nonzero) digits is 18816, while the sum is 38.

The square root of 81107687 is about 9005.9806240076. The cubic root of 81107687 is about 432.8665288119.

The spelling of 81107687 in words is "eighty-one million, one hundred seven thousand, six hundred eighty-seven".