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25569 = 33947

25569 has 8 divisors (see below), whose sum is σ = 37920. Its totient is φ = 17028.

The previous prime is 25561. The next prime is 25577. The reversal of 25569 is 96552.

25569 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (25561) and next prime (25577).

It is not a de Polignac number, because 25569 - 23 = 25561 is a prime.

It is a super-2 number, since 2×255692 = 1307547522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 947 = 25569 / (2 + 5 + 5 + 6 + 9).

25569 is a lucky number.

It is a plaindrome in base 10 and base 15.

It is not an unprimeable number, because it can be changed into a prime (25561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 447 + ... + 500.

It is an arithmetic number, because the mean of its divisors is an integer number (4740).

225569 is an apocalyptic number.

It is an amenable number.

25569 is a deficient number, since it is larger than the sum of its proper divisors (12351).

25569 is an equidigital number, since it uses as much as digits as its factorization.

25569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956 (or 950 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 25569 is about 159.9030956548. The cubic root of 25569 is about 29.4603508323.

It can be divided in two parts, 255 and 69, that added together give a square (324 = 182).

The spelling of 25569 in words is "twenty-five thousand, five hundred sixty-nine".

Divisors: 1 3 9 27 947 2841 8523 25569