25601591 has 4 divisors (see below), whose sum is σ = 25619184. Its totient is φ = 25584000.

The previous prime is 25601561. The next prime is 25601603. The reversal of 25601591 is 19510652.

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 25601591 - 2¹⁰ = 25600567 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 (25601561) 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, 6395 + ... + 9596.

It is an arithmetic number, because the mean of its divisors is an integer number (6404796).

Almost surely, 2^25601591 is an apocalyptic number.

25601591 is a deficient number, since it is larger than the sum of its proper divisors (17593).

25601591 is a wasteful number, since it uses less digits than its factorization.

25601591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17592.

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 25601591 is about 5059.8014783191. The cubic root of 25601591 is about 294.7286252795.

The spelling of 25601591 in words is "twenty-five million, six hundred one thousand, five hundred ninety-one".