26391 has 8 divisors (see below), whose sum is σ = 37120. Its totient is φ = 16632.

The previous prime is 26387. The next prime is 26393. The reversal of 26391 is 19362.

Added to its reverse (19362) it gives a triangular number (45753 = T₃₀₂).

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

It is not a de Polignac number, because 26391 - 2² = 26387 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26393) 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, 175 + ... + 288.

It is an arithmetic number, because the mean of its divisors is an integer number (4640).

2²⁶³⁹¹ is an apocalyptic number.

26391 is a deficient number, since it is larger than the sum of its proper divisors (10729).

26391 is a wasteful number, since it uses less digits than its factorization.

26391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485.

The product of its digits is 324, while the sum is 21.

The square root of 26391 is about 162.4530701464. The cubic root of 26391 is about 29.7727270255.

Adding to 26391 its reverse (19362), we get a triangular number (45753 = T₃₀₂).

The spelling of 26391 in words is "twenty-six thousand, three hundred ninety-one".