25551681 has 16 divisors (see below), whose sum is σ = 34805760. Its totient is φ = 16670160.

The previous prime is 25551667. The next prime is 25551683. The reversal of 25551681 is 18615552.

It is not a de Polignac number, because 25551681 - 2⁵ = 25551649 is a prime.

It is a super-2 number, since 2×25551681² = 1305776803851522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25551683) 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 15 ways as a sum of consecutive naturals, for example, 30636 + ... + 31458.

It is an arithmetic number, because the mean of its divisors is an integer number (2175360).

Almost surely, 2^25551681 is an apocalyptic number.

It is an amenable number.

25551681 is a deficient number, since it is larger than the sum of its proper divisors (9254079).

25551681 is a wasteful number, since it uses less digits than its factorization.

25551681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036.

The product of its digits is 12000, while the sum is 33.

The square root of 25551681 is about 5054.8670605665. The cubic root of 25551681 is about 294.5369773596.

The spelling of 25551681 in words is "twenty-five million, five hundred fifty-one thousand, six hundred eighty-one".