26390991 has 8 divisors (see below), whose sum is σ = 38386944. Its totient is φ = 15994520.

The previous prime is 26390989. The next prime is 26390999. The reversal of 26390991 is 19909362.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 26390991 - 2¹ = 26390989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26390999) 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, 399831 + ... + 399896.

It is an arithmetic number, because the mean of its divisors is an integer number (4798368).

Almost surely, 2^26390991 is an apocalyptic number.

26390991 is a deficient number, since it is larger than the sum of its proper divisors (11995953).

26390991 is a wasteful number, since it uses less digits than its factorization.

26390991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799741.

The product of its (nonzero) digits is 26244, while the sum is 39.

The square root of 26390991 is about 5137.2162695374. The cubic root of 26390991 is about 297.7272364110.

The spelling of 26390991 in words is "twenty-six million, three hundred ninety thousand, nine hundred ninety-one".