25691281 has 32 divisors (see below), whose sum is σ = 33914880. Its totient is φ = 18878400.

The previous prime is 25691261. The next prime is 25691293. The reversal of 25691281 is 18219652.

It is a cyclic number.

It is not a de Polignac number, because 25691281 - 2⁷ = 25691153 is a prime.

It is a super-2 number, since 2×25691281² = 1320083838841922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25691201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112075 + ... + 112303.

It is an arithmetic number, because the mean of its divisors is an integer number (1059840).

Almost surely, 2^25691281 is an apocalyptic number.

25691281 is the 3206-th heptagonal number.

It is an amenable number.

25691281 is a deficient number, since it is larger than the sum of its proper divisors (8223599).

25691281 is a wasteful number, since it uses less digits than its factorization.

25691281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325.

The product of its digits is 8640, while the sum is 34.

The square root of 25691281 is about 5068.6567254057. The cubic root of 25691281 is about 295.0723982032.

The spelling of 25691281 in words is "twenty-five million, six hundred ninety-one thousand, two hundred eighty-one".