25188991 has 2 divisors, whose sum is σ = 25188992. Its totient is φ = 25188990.

The previous prime is 25188953. The next prime is 25188997. The reversal of 25188991 is 19988152.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25188991 - 2⁹ = 25188479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25188997) 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, 12594495 + 12594496.

It is an arithmetic number, because the mean of its divisors is an integer number (12594496).

Almost surely, 2^25188991 is an apocalyptic number.

25188991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25188991 is an equidigital number, since it uses as much as digits as its factorization.

25188991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 43.

The square root of 25188991 is about 5018.8635167735. The cubic root of 25188991 is about 293.1367422704.

The spelling of 25188991 in words is "twenty-five million, one hundred eighty-eight thousand, nine hundred ninety-one".