91687 has 4 divisors (see below), whose sum is σ = 92296. Its totient is φ = 91080.

The previous prime is 91673. The next prime is 91691. The reversal of 91687 is 78619.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 78619 = 29 ⋅2711.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91387) 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, 112 + ... + 442.

It is an arithmetic number, because the mean of its divisors is an integer number (23074).

2⁹¹⁶⁸⁷ is an apocalyptic number.

91687 is a deficient number, since it is larger than the sum of its proper divisors (609).

91687 is a wasteful number, since it uses less digits than its factorization.

91687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608.

The product of its digits is 3024, while the sum is 31.

The square root of 91687 is about 302.7986129427. The cubic root of 91687 is about 45.0923207558.

The spelling of 91687 in words is "ninety-one thousand, six hundred eighty-seven".