25581601 has 2 divisors, whose sum is σ = 25581602. Its totient is φ = 25581600.

The previous prime is 25581559. The next prime is 25581607. The reversal of 25581601 is 10618552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 5645376 = 4465^2 + 2376^2 .

It is a cyclic number.

It is not a de Polignac number, because 25581601 - 2⁷ = 25581473 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25581601.

It is not a weakly prime, because it can be changed into another prime (25581607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12790800 + 12790801.

It is an arithmetic number, because the mean of its divisors is an integer number (12790801).

Almost surely, 2^25581601 is an apocalyptic number.

It is an amenable number.

25581601 is a deficient number, since it is larger than the sum of its proper divisors (1).

25581601 is an equidigital number, since it uses as much as digits as its factorization.

25581601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 25581601 is about 5057.8257186265. The cubic root of 25581601 is about 294.6518962030.

The spelling of 25581601 in words is "twenty-five million, five hundred eighty-one thousand, six hundred one".