2491639 has 8 divisors (see below), whose sum is σ = 2667168. Its totient is φ = 2319360.

The previous prime is 2491609. The next prime is 2491649. The reversal of 2491639 is 9361942.

2491639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2491639 - 2⁵ = 2491607 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 (2491609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 894 + ... + 2404.

It is an arithmetic number, because the mean of its divisors is an integer number (333396).

2^2491639 is an apocalyptic number.

2491639 is a deficient number, since it is larger than the sum of its proper divisors (175529).

2491639 is a wasteful number, since it uses less digits than its factorization.

2491639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1625.

The product of its digits is 11664, while the sum is 34.

The square root of 2491639 is about 1578.4926353962. The cubic root of 2491639 is about 135.5694102066.

The spelling of 2491639 in words is "two million, four hundred ninety-one thousand, six hundred thirty-nine".