25781089 has 2 divisors, whose sum is σ = 25781090. Its totient is φ = 25781088.

The previous prime is 25781083. The next prime is 25781099. The reversal of 25781089 is 98018752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17572864 + 8208225 = 4192^2 + 2865^2 .

It is a cyclic number.

It is not a de Polignac number, because 25781089 - 2⁷ = 25780961 is a prime.

It is not a weakly prime, because it can be changed into another prime (25781083) 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 as a sum of consecutive naturals, namely, 12890544 + 12890545.

It is an arithmetic number, because the mean of its divisors is an integer number (12890545).

Almost surely, 2^25781089 is an apocalyptic number.

It is an amenable number.

25781089 is a deficient number, since it is larger than the sum of its proper divisors (1).

25781089 is an equidigital number, since it uses as much as digits as its factorization.

25781089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 25781089 is about 5077.5081486887. The cubic root of 25781089 is about 295.4158226720.

The spelling of 25781089 in words is "twenty-five million, seven hundred eighty-one thousand, eighty-nine".