25809791 has 16 divisors (see below), whose sum is σ = 31539456. Its totient is φ = 20616576.

The previous prime is 25809767. The next prime is 25809811. The reversal of 25809791 is 19790852.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25809791 is a prime.

It is a super-2 number, since 2×25809791² = 1332290622927362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25809191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11720 + ... + 13746.

It is an arithmetic number, because the mean of its divisors is an integer number (1971216).

Almost surely, 2^25809791 is an apocalyptic number.

25809791 is a deficient number, since it is larger than the sum of its proper divisors (5729665).

25809791 is a wasteful number, since it uses less digits than its factorization.

25809791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2158.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 25809791 is about 5080.3337488791. Note that the first 3 decimals coincide. The cubic root of 25809791 is about 295.5254104959.

The spelling of 25809791 in words is "twenty-five million, eight hundred nine thousand, seven hundred ninety-one".