25726991 has 4 divisors (see below), whose sum is σ = 25833984. Its totient is φ = 25620000.

The previous prime is 25726979. The next prime is 25727011. The reversal of 25726991 is 19962752.

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 25726991 - 2¹⁸ = 25464847 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 (25726901) 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, 53135 + ... + 53616.

It is an arithmetic number, because the mean of its divisors is an integer number (6458496).

Almost surely, 2^25726991 is an apocalyptic number.

25726991 is a deficient number, since it is larger than the sum of its proper divisors (106993).

25726991 is a wasteful number, since it uses less digits than its factorization.

25726991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106992.

The product of its digits is 68040, while the sum is 41.

The square root of 25726991 is about 5072.1781317300. The cubic root of 25726991 is about 295.2090484162.

The spelling of 25726991 in words is "twenty-five million, seven hundred twenty-six thousand, nine hundred ninety-one".