25664161 has 4 divisors (see below), whose sum is σ = 25677972. Its totient is φ = 25650352.

The previous prime is 25664143. The next prime is 25664173. The reversal of 25664161 is 16146652.

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 24443136 + 1221025 = 4944^2 + 1105^2 .

It is a cyclic number.

It is not a de Polignac number, because 25664161 - 2¹¹ = 25662113 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25664761) 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, 3586 + ... + 8011.

It is an arithmetic number, because the mean of its divisors is an integer number (6419493).

Almost surely, 2^25664161 is an apocalyptic number.

It is an amenable number.

25664161 is a deficient number, since it is larger than the sum of its proper divisors (13811).

25664161 is a wasteful number, since it uses less digits than its factorization.

25664161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13810.

The product of its digits is 8640, while the sum is 31.

The square root of 25664161 is about 5065.9807540100. The cubic root of 25664161 is about 294.9685344204.

The spelling of 25664161 in words is "twenty-five million, six hundred sixty-four thousand, one hundred sixty-one".