4991491 has 2 divisors, whose sum is σ = 4991492. Its totient is φ = 4991490.

The previous prime is 4991479. The next prime is 4991507. The reversal of 4991491 is 1941994.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4991491 - 2¹¹ = 4989443 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4991491.

It is not a weakly prime, because it can be changed into another prime (4991401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2495745 + 2495746.

It is an arithmetic number, because the mean of its divisors is an integer number (2495746).

Almost surely, 2^4991491 is an apocalyptic number.

4991491 is a deficient number, since it is larger than the sum of its proper divisors (1).

4991491 is an equidigital number, since it uses as much as digits as its factorization.

4991491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 4991491 is about 2234.1644970772. The cubic root of 4991491 is about 170.9005383545.

It can be divided in two parts, 49914 and 91, that added together give a palindrome (50005).

The spelling of 4991491 in words is "four million, nine hundred ninety-one thousand, four hundred ninety-one".