25581553 has 2 divisors, whose sum is σ = 25581554. Its totient is φ = 25581552.

The previous prime is 25581551. The next prime is 25581559. The reversal of 25581553 is 35518552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22543504 + 3038049 = 4748^2 + 1743^2 .

It is a cyclic number.

It is not a de Polignac number, because 25581553 - 2¹ = 25581551 is a prime.

Together with 25581551, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25581551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12790776 + 12790777.

It is an arithmetic number, because the mean of its divisors is an integer number (12790777).

Almost surely, 2^25581553 is an apocalyptic number.

It is an amenable number.

25581553 is a deficient number, since it is larger than the sum of its proper divisors (1).

25581553 is an equidigital number, since it uses as much as digits as its factorization.

25581553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30000, while the sum is 34.

The square root of 25581553 is about 5057.8209735023. The cubic root of 25581553 is about 294.6517119130.

The spelling of 25581553 in words is "twenty-five million, five hundred eighty-one thousand, five hundred fifty-three".