25517521 has 2 divisors, whose sum is σ = 25517522. Its totient is φ = 25517520.

The previous prime is 25517497. The next prime is 25517537. The reversal of 25517521 is 12571552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22043025 + 3474496 = 4695^2 + 1864^2 .

It is a cyclic number.

It is not a de Polignac number, because 25517521 - 2¹¹ = 25515473 is a prime.

It is a super-2 number, since 2×25517521² = 1302287755970882, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25517521.

It is not a weakly prime, because it can be changed into another prime (25517021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12758760 + 12758761.

It is an arithmetic number, because the mean of its divisors is an integer number (12758761).

Almost surely, 2^25517521 is an apocalyptic number.

It is an amenable number.

25517521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25517521 is an equidigital number, since it uses as much as digits as its factorization.

25517521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3500, while the sum is 28.

The square root of 25517521 is about 5051.4870087926. The cubic root of 25517521 is about 294.4056634920.

The spelling of 25517521 in words is "twenty-five million, five hundred seventeen thousand, five hundred twenty-one".