25443521 has 4 divisors (see below), whose sum is σ = 25469652. Its totient is φ = 25417392.

The previous prime is 25443499. The next prime is 25443553. The reversal of 25443521 is 12534452.

It is a happy number.

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 5013121 + 20430400 = 2239^2 + 4520^2 .

It is a cyclic number.

It is not a de Polignac number, because 25443521 - 2¹⁰ = 25442497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25443581) 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, 11546 + ... + 13571.

It is an arithmetic number, because the mean of its divisors is an integer number (6367413).

Almost surely, 2^25443521 is an apocalyptic number.

It is an amenable number.

25443521 is a deficient number, since it is larger than the sum of its proper divisors (26131).

25443521 is a wasteful number, since it uses less digits than its factorization.

25443521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26130.

The product of its digits is 4800, while the sum is 26.

The square root of 25443521 is about 5044.1571149202. The cubic root of 25443521 is about 294.1207989254.

Adding to 25443521 its reverse (12534452), we get a palindrome (37977973).

The spelling of 25443521 in words is "twenty-five million, four hundred forty-three thousand, five hundred twenty-one".