25905561 has 8 divisors (see below), whose sum is σ = 37680864. Its totient is φ = 15700320.

The previous prime is 25905559. The next prime is 25905577. The reversal of 25905561 is 16550952.

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

It is not a de Polignac number, because 25905561 - 2¹ = 25905559 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 785017 = 25905561 / (2 + 5 + 9 + 0 + 5 + 5 + 6 + 1).

It is not an unprimeable number, because it can be changed into a prime (25905361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392476 + ... + 392541.

It is an arithmetic number, because the mean of its divisors is an integer number (4710108).

Almost surely, 2^25905561 is an apocalyptic number.

It is an amenable number.

25905561 is a deficient number, since it is larger than the sum of its proper divisors (11775303).

25905561 is a wasteful number, since it uses less digits than its factorization.

25905561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 785031.

The product of its (nonzero) digits is 13500, while the sum is 33.

The square root of 25905561 is about 5089.7505832801. The cubic root of 25905561 is about 295.8904855702.

The spelling of 25905561 in words is "twenty-five million, nine hundred five thousand, five hundred sixty-one".