25216505 has 4 divisors (see below), whose sum is σ = 30259812. Its totient is φ = 20173200.

The previous prime is 25216493. The next prime is 25216507. The reversal of 25216505 is 50561252.

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 16168441 + 9048064 = 4021^2 + 3008^2 .

It is not a de Polignac number, because 25216505 - 2¹⁰ = 25215481 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25216507) 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, 2521646 + ... + 2521655.

It is an arithmetic number, because the mean of its divisors is an integer number (7564953).

Almost surely, 2^25216505 is an apocalyptic number.

It is an amenable number.

25216505 is a deficient number, since it is larger than the sum of its proper divisors (5043307).

25216505 is an equidigital number, since it uses as much as digits as its factorization.

25216505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5043306.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 25216505 is about 5021.6038274639. The cubic root of 25216505 is about 293.2434347735.

Adding to 25216505 its reverse (50561252), we get a palindrome (75777757).

The spelling of 25216505 in words is "twenty-five million, two hundred sixteen thousand, five hundred five".