25440521 has 2 divisors, whose sum is σ = 25440522. Its totient is φ = 25440520.

The previous prime is 25440479. The next prime is 25440529. The reversal of 25440521 is 12504452.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14714896 + 10725625 = 3836^2 + 3275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25440521 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25440529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12720260 + 12720261.

It is an arithmetic number, because the mean of its divisors is an integer number (12720261).

Almost surely, 2^25440521 is an apocalyptic number.

It is an amenable number.

25440521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25440521 is an equidigital number, since it uses as much as digits as its factorization.

25440521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 25440521 is about 5043.8597323875. The cubic root of 25440521 is about 294.1092387188.

Adding to 25440521 its reverse (12504452), we get a palindrome (37944973).

The spelling of 25440521 in words is "twenty-five million, four hundred forty thousand, five hundred twenty-one".