26013991 has 4 divisors (see below), whose sum is σ = 26853184. Its totient is φ = 25174800.

The previous prime is 26013959. The next prime is 26014003. The reversal of 26013991 is 19931062.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 26013991 - 2⁵ = 26013959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 839161 = 26013991 / (2 + 6 + 0 + 1 + 3 + 9 + 9 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26010991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 419550 + ... + 419611.

It is an arithmetic number, because the mean of its divisors is an integer number (6713296).

Almost surely, 2^26013991 is an apocalyptic number.

26013991 is a deficient number, since it is larger than the sum of its proper divisors (839193).

26013991 is an equidigital number, since it uses as much as digits as its factorization.

26013991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839192.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 26013991 is about 5100.3912595016. The cubic root of 26013991 is about 296.3027361357.

The spelling of 26013991 in words is "twenty-six million, thirteen thousand, nine hundred ninety-one".