25525781 has 2 divisors, whose sum is σ = 25525782. Its totient is φ = 25525780.

The previous prime is 25525777. The next prime is 25525793. The reversal of 25525781 is 18752552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24900100 + 625681 = 4990^2 + 791^2 .

It is a cyclic number.

It is not a de Polignac number, because 25525781 - 2² = 25525777 is a prime.

It is a super-2 number, since 2×25525781² = 1303130991319922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_1596671 and since 25525781 and 1596671 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25525081) 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, 12762890 + 12762891.

It is an arithmetic number, because the mean of its divisors is an integer number (12762891).

Almost surely, 2^25525781 is an apocalyptic number.

It is an amenable number.

25525781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25525781 is an equidigital number, since it uses as much as digits as its factorization.

25525781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28000, while the sum is 35.

The square root of 25525781 is about 5052.3045236803. The cubic root of 25525781 is about 294.4374263533.

The spelling of 25525781 in words is "twenty-five million, five hundred twenty-five thousand, seven hundred eighty-one".