26409 has 4 divisors (see below), whose sum is σ = 35216. Its totient is φ = 17604.

The previous prime is 26407. The next prime is 26417. The reversal of 26409 is 90462.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 26409 - 2¹ = 26407 is a prime.

It is a D-number.

It is a Duffinian number.

26409 is a lucky number.

It is a plaindrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 26409.

It is not an unprimeable number, because it can be changed into a prime (26407) 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, 4399 + ... + 4404.

It is an arithmetic number, because the mean of its divisors is an integer number (8804).

2²⁶⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

26409 is a deficient number, since it is larger than the sum of its proper divisors (8807).

26409 is an equidigital number, since it uses as much as digits as its factorization.

26409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8806.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 26409 is about 162.5084613182. The cubic root of 26409 is about 29.7794943236.

It can be divided in two parts, 26 and 409, that added together give a triangular number (435 = T₂₉).

The spelling of 26409 in words is "twenty-six thousand, four hundred nine".