2491943 has 4 divisors (see below), whose sum is σ = 2497248. Its totient is φ = 2486640.

The previous prime is 2491933. The next prime is 2491949. The reversal of 2491943 is 3491942.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3491942 = 2 ⋅1745971.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2491943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2491949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1871 + ... + 2912.

It is an arithmetic number, because the mean of its divisors is an integer number (624312).

2^2491943 is an apocalyptic number.

2491943 is a deficient number, since it is larger than the sum of its proper divisors (5305).

2491943 is an equidigital number, since it uses as much as digits as its factorization.

2491943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5304.

The product of its digits is 7776, while the sum is 32.

The square root of 2491943 is about 1578.5889268584. The cubic root of 2491943 is about 135.5749235019.

Subtracting 2491943 from its reverse (3491942), we obtain a palindrome (999999).

The spelling of 2491943 in words is "two million, four hundred ninety-one thousand, nine hundred forty-three".