25687993 has 2 divisors, whose sum is σ = 25687994. Its totient is φ = 25687992.

The previous prime is 25687973. The next prime is 25688009. The reversal of 25687993 is 39978652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23736384 + 1951609 = 4872^2 + 1397^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25687993 is a prime.

It is not a weakly prime, because it can be changed into another prime (25687903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12843996 + 12843997.

It is an arithmetic number, because the mean of its divisors is an integer number (12843997).

Almost surely, 2^25687993 is an apocalyptic number.

It is an amenable number.

25687993 is a deficient number, since it is larger than the sum of its proper divisors (1).

25687993 is an equidigital number, since it uses as much as digits as its factorization.

25687993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 49.

The square root of 25687993 is about 5068.3323687383. The cubic root of 25687993 is about 295.0598097633.

The spelling of 25687993 in words is "twenty-five million, six hundred eighty-seven thousand, nine hundred ninety-three".