4188991 has 2 divisors, whose sum is σ = 4188992. Its totient is φ = 4188990.

The previous prime is 4188973. The next prime is 4188997. The reversal of 4188991 is 1998814.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 4188991 - 2⁹ = 4188479 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4188997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2094495 + 2094496.

It is an arithmetic number, because the mean of its divisors is an integer number (2094496).

Almost surely, 2^4188991 is an apocalyptic number.

4188991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4188991 is an equidigital number, since it uses as much as digits as its factorization.

4188991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 40.

The square root of 4188991 is about 2046.7024698280. The cubic root of 4188991 is about 161.2017711262.

It can be divided in two parts, 418 and 8991, that added together give a square (9409 = 97²).

The spelling of 4188991 in words is "four million, one hundred eighty-eight thousand, nine hundred ninety-one".