25561555 has 8 divisors (see below), whose sum is σ = 32288400. Its totient is φ = 19372896.

The previous prime is 25561553. The next prime is 25561559. The reversal of 25561555 is 55516552.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25561555 - 2¹ = 25561553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25561555.

It is not an unprimeable number, because it can be changed into a prime (25561553) 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 7 ways as a sum of consecutive naturals, for example, 134440 + ... + 134629.

It is an arithmetic number, because the mean of its divisors is an integer number (4036050).

Almost surely, 2^25561555 is an apocalyptic number.

25561555 is a deficient number, since it is larger than the sum of its proper divisors (6726845).

25561555 is a wasteful number, since it uses less digits than its factorization.

25561555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269093.

The product of its digits is 37500, while the sum is 34.

The square root of 25561555 is about 5055.8436486901. The cubic root of 25561555 is about 294.5749120272.

The spelling of 25561555 in words is "twenty-five million, five hundred sixty-one thousand, five hundred fifty-five".