25809145 has 24 divisors (see below), whose sum is σ = 33620184. Its totient is φ = 19009536.

The previous prime is 25809109. The next prime is 25809181. The reversal of 25809145 is 54190852.

It is an interprime number because it is at equal distance from previous prime (25809109) and next prime (25809181).

It can be written as a sum of positive squares in 12 ways, for example, as 769129 + 25040016 = 877^2 + 5004^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25809145 is a prime.

It is a super-2 number, since 2×25809145² = 1332223931262050, which contains 22 as substring.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25809145.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76417 + ... + 76753.

It is an arithmetic number, because the mean of its divisors is an integer number (1400841).

Almost surely, 2^25809145 is an apocalyptic number.

It is an amenable number.

25809145 is a deficient number, since it is larger than the sum of its proper divisors (7811039).

25809145 is a wasteful number, since it uses less digits than its factorization.

25809145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429 (or 412 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 25809145 is about 5080.2701699811. The cubic root of 25809145 is about 295.5229448811.

Adding to 25809145 its reverse (54190852), we get a palindrome (79999997).

The spelling of 25809145 in words is "twenty-five million, eight hundred nine thousand, one hundred forty-five".