25401521 has 2 divisors, whose sum is σ = 25401522. Its totient is φ = 25401520.

The previous prime is 25401517. The next prime is 25401529. The reversal of 25401521 is 12510452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25391521 + 10000 = 5039^2 + 100^2 .

It is a cyclic number.

It is not a de Polignac number, because 25401521 - 2² = 25401517 is a prime.

It is a super-2 number, since 2×25401521² = 1290474538226882, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 25401493 and 25401502.

It is not a weakly prime, because it can be changed into another prime (25401529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12700760 + 12700761.

It is an arithmetic number, because the mean of its divisors is an integer number (12700761).

Almost surely, 2^25401521 is an apocalyptic number.

It is an amenable number.

25401521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25401521 is an equidigital number, since it uses as much as digits as its factorization.

25401521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 25401521 is about 5039.9921626923. The cubic root of 25401521 is about 293.9588732636.

Adding to 25401521 its reverse (12510452), we get a palindrome (37911973).

The spelling of 25401521 in words is "twenty-five million, four hundred one thousand, five hundred twenty-one".