25993991 has 4 divisors (see below), whose sum is σ = 26420184. Its totient is φ = 25567800.

The previous prime is 25993967. The next prime is 25994011. The reversal of 25993991 is 19939952.

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-25993991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25993921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213005 + ... + 213126.

It is an arithmetic number, because the mean of its divisors is an integer number (6605046).

Almost surely, 2^25993991 is an apocalyptic number.

25993991 is a deficient number, since it is larger than the sum of its proper divisors (426193).

25993991 is an equidigital number, since it uses as much as digits as its factorization.

25993991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426192.

The product of its digits is 196830, while the sum is 47.

The square root of 25993991 is about 5098.4302486157. The cubic root of 25993991 is about 296.2267824683.

The spelling of 25993991 in words is "twenty-five million, nine hundred ninety-three thousand, nine hundred ninety-one".