26691 has 16 divisors (see below), whose sum is σ = 43008. Its totient is φ = 14400.

The previous prime is 26687. The next prime is 26693. The reversal of 26691 is 19662.

26691 is nontrivially palindromic in base 5 and base 6.

It is not a de Polignac number, because 26691 - 2² = 26687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 631 + ... + 671.

It is an arithmetic number, because the mean of its divisors is an integer number (2688).

2²⁶⁶⁹¹ is an apocalyptic number.

26691 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

26691 is a deficient number, since it is larger than the sum of its proper divisors (16317).

26691 is a wasteful number, since it uses less digits than its factorization.

26691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82.

The product of its digits is 648, while the sum is 24.

The square root of 26691 is about 163.3738045098. The cubic root of 26691 is about 29.8851161740.

It can be divided in two parts, 26 and 691, that added together give a palindrome (717).

The spelling of 26691 in words is "twenty-six thousand, six hundred ninety-one".