100691 has 4 divisors (see below), whose sum is σ = 106632. Its totient is φ = 94752.

The previous prime is 100673. The next prime is 100693. The reversal of 100691 is 196001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196001 = 13 ⋅15077.

It is a cyclic number.

It is not a de Polignac number, because 100691 - 2¹⁰ = 99667 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 5923 = 100691 / (1 + 0 + 0 + 6 + 9 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100693) 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, 2945 + ... + 2978.

It is an arithmetic number, because the mean of its divisors is an integer number (26658).

2¹⁰⁰⁶⁹¹ is an apocalyptic number.

100691 is a deficient number, since it is larger than the sum of its proper divisors (5941).

100691 is an equidigital number, since it uses as much as digits as its factorization.

100691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5940.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 100691 is about 317.3184520320. The cubic root of 100691 is about 46.5225542877.

Adding to 100691 its reverse (196001), we get a palindrome (296692).

The spelling of 100691 in words is "one hundred thousand, six hundred ninety-one".