25457681 has 2 divisors, whose sum is σ = 25457682. Its totient is φ = 25457680.

The previous prime is 25457639. The next prime is 25457683. The reversal of 25457681 is 18675452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24910081 + 547600 = 4991^2 + 740^2 .

It is a cyclic number.

It is not a de Polignac number, because 25457681 - 2⁶ = 25457617 is a prime.

It is a super-2 number, since 2×25457681² = 1296187043795522, which contains 22 as substring.

Together with 25457683, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 25457681 parts by 7135 straight cuts.

It is not a weakly prime, because it can be changed into another prime (25457683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12728840 + 12728841.

It is an arithmetic number, because the mean of its divisors is an integer number (12728841).

Almost surely, 2^25457681 is an apocalyptic number.

It is an amenable number.

25457681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25457681 is an equidigital number, since it uses as much as digits as its factorization.

25457681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67200, while the sum is 38.

The square root of 25457681 is about 5045.5605238665. The cubic root of 25457681 is about 294.1753508374.

The spelling of 25457681 in words is "twenty-five million, four hundred fifty-seven thousand, six hundred eighty-one".