26840391 has 4 divisors (see below), whose sum is σ = 35787192. Its totient is φ = 17893592.

The previous prime is 26840351. The next prime is 26840423. The reversal of 26840391 is 19304862.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26840391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26840311) 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, 4473396 + ... + 4473401.

It is an arithmetic number, because the mean of its divisors is an integer number (8946798).

Almost surely, 2^26840391 is an apocalyptic number.

26840391 is a deficient number, since it is larger than the sum of its proper divisors (8946801).

26840391 is an equidigital number, since it uses as much as digits as its factorization.

26840391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8946800.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 26840391 is about 5180.7712746270. The cubic root of 26840391 is about 299.4076868757.

The spelling of 26840391 in words is "twenty-six million, eight hundred forty thousand, three hundred ninety-one".