25644121 has 2 divisors, whose sum is σ = 25644122. Its totient is φ = 25644120.

The previous prime is 25644119. The next prime is 25644133. The reversal of 25644121 is 12144652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25644096 + 25 = 5064^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 25644121 - 2¹ = 25644119 is a prime.

It is a super-3 number, since 3×25644121³ (a number of 23 digits) contains 333 as substring.

Together with 25644119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25644191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12822060 + 12822061.

It is an arithmetic number, because the mean of its divisors is an integer number (12822061).

Almost surely, 2^25644121 is an apocalyptic number.

It is an amenable number.

25644121 is a deficient number, since it is larger than the sum of its proper divisors (1).

25644121 is an equidigital number, since it uses as much as digits as its factorization.

25644121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 25.

The square root of 25644121 is about 5064.0024684038. The cubic root of 25644121 is about 294.8917384988.

Subtracting from 25644121 its sum of digits (25), we obtain a square (25644096 = 5064²).

Adding to 25644121 its reverse (12144652), we get a palindrome (37788773).

The spelling of 25644121 in words is "twenty-five million, six hundred forty-four thousand, one hundred twenty-one".