25216109 has 4 divisors (see below), whose sum is σ = 26085660. Its totient is φ = 24346560.

The previous prime is 25216091. The next prime is 25216127. The reversal of 25216109 is 90161252.

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

It is an interprime number because it is at equal distance from previous prime (25216091) and next prime (25216127).

It can be written as a sum of positive squares in 2 ways, for example, as 8282884 + 16933225 = 2878^2 + 4115^2 .

It is a cyclic number.

It is not a de Polignac number, because 25216109 - 2¹² = 25212013 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25216159) 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, 434732 + ... + 434789.

It is an arithmetic number, because the mean of its divisors is an integer number (6521415).

Almost surely, 2^25216109 is an apocalyptic number.

25216109 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

25216109 is a deficient number, since it is larger than the sum of its proper divisors (869551).

25216109 is an equidigital number, since it uses as much as digits as its factorization.

25216109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869550.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 25216109 is about 5021.5643976753. The cubic root of 25216109 is about 293.2418997338.

It can be divided in two parts, 252 and 16109, that added together give a palindrome (16361).

The spelling of 25216109 in words is "twenty-five million, two hundred sixteen thousand, one hundred nine".