25556161 has 4 divisors (see below), whose sum is σ = 26179524. Its totient is φ = 24932800.

The previous prime is 25556129. The next prime is 25556173. The reversal of 25556161 is 16165552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1113025 + 24443136 = 1055^2 + 4944^2 .

It is a cyclic number.

It is not a de Polignac number, because 25556161 - 2⁵ = 25556129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25556191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311620 + ... + 311701.

It is an arithmetic number, because the mean of its divisors is an integer number (6544881).

Almost surely, 2^25556161 is an apocalyptic number.

It is an amenable number.

25556161 is a deficient number, since it is larger than the sum of its proper divisors (623363).

25556161 is an equidigital number, since it uses as much as digits as its factorization.

25556161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623362.

The product of its digits is 9000, while the sum is 31.

The square root of 25556161 is about 5055.3101784164. The cubic root of 25556161 is about 294.5541901677.

The spelling of 25556161 in words is "twenty-five million, five hundred fifty-six thousand, one hundred sixty-one".