2491645 has 8 divisors (see below), whose sum is σ = 3220056. Its totient is φ = 1839936.

The previous prime is 2491609. The next prime is 2491649. The reversal of 2491645 is 5461942.

2491645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 116964 + 2374681 = 342^2 + 1541^2 .

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-2491645 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 (2491649) 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, 19102 + ... + 19231.

It is an arithmetic number, because the mean of its divisors is an integer number (402507).

2^2491645 is an apocalyptic number.

It is an amenable number.

2491645 is a deficient number, since it is larger than the sum of its proper divisors (728411).

2491645 is a wasteful number, since it uses less digits than its factorization.

2491645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38351.

The product of its digits is 8640, while the sum is 31.

The square root of 2491645 is about 1578.4945359424. The cubic root of 2491645 is about 135.5695190260.

It can be divided in two parts, 2491 and 645, that added together give a square (3136 = 56²).

The spelling of 2491645 in words is "two million, four hundred ninety-one thousand, six hundred forty-five".