4989991 has 2 divisors, whose sum is σ = 4989992. Its totient is φ = 4989990.

The previous prime is 4989979. The next prime is 4989997. The reversal of 4989991 is 1999894.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 4989991 - 2⁷ = 4989863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4989997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2494995 + 2494996.

It is an arithmetic number, because the mean of its divisors is an integer number (2494996).

Almost surely, 2^4989991 is an apocalyptic number.

4989991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4989991 is an equidigital number, since it uses as much as digits as its factorization.

4989991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 49.

The square root of 4989991 is about 2233.8287758913. The cubic root of 4989991 is about 170.8834174521.

The spelling of 4989991 in words is "four million, nine hundred eighty-nine thousand, nine hundred ninety-one".