4991989 has 8 divisors (see below), whose sum is σ = 5253120. Its totient is φ = 4734576.

The previous prime is 4991983. The next prime is 4992007. The reversal of 4991989 is 9891994.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4991989 is a prime.

It is a super-2 number, since 2×4991989² = 49839908352242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4991983) 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 in 7 ways as a sum of consecutive naturals, for example, 2067 + ... + 3775.

It is an arithmetic number, because the mean of its divisors is an integer number (656640).

Almost surely, 2^4991989 is an apocalyptic number.

It is an amenable number.

4991989 is a deficient number, since it is larger than the sum of its proper divisors (261131).

4991989 is a wasteful number, since it uses less digits than its factorization.

4991989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859.

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

The square root of 4991989 is about 2234.2759453568. The cubic root of 4991989 is about 170.9062217357.

The spelling of 4991989 in words is "four million, nine hundred ninety-one thousand, nine hundred eighty-nine".