25775209 has 2 divisors, whose sum is σ = 25775210. Its totient is φ = 25775208.

The previous prime is 25775207. The next prime is 25775219. The reversal of 25775209 is 90257752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24157225 + 1617984 = 4915^2 + 1272^2 .

It is a cyclic number.

It is not a de Polignac number, because 25775209 - 2¹ = 25775207 is a prime.

It is a super-2 number, since 2×25775209² = 1328722797987362, which contains 22 as substring.

Together with 25775207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25775207) 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, 12887604 + 12887605.

It is an arithmetic number, because the mean of its divisors is an integer number (12887605).

Almost surely, 2^25775209 is an apocalyptic number.

It is an amenable number.

25775209 is a deficient number, since it is larger than the sum of its proper divisors (1).

25775209 is an equidigital number, since it uses as much as digits as its factorization.

25775209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44100, while the sum is 37.

The square root of 25775209 is about 5076.9290914883. The cubic root of 25775209 is about 295.3933620599.

It can be divided in two parts, 257 and 75209, that added together give a triangular number (75466 = T₃₈₈).

The spelling of 25775209 in words is "twenty-five million, seven hundred seventy-five thousand, two hundred nine".