2491665 has 16 divisors (see below), whose sum is σ = 4349376. Its totient is φ = 1208000.

The previous prime is 2491661. The next prime is 2491669. The reversal of 2491665 is 5661942.

It is an interprime number because it is at equal distance from previous prime (2491661) and next prime (2491669).

It is not a de Polignac number, because 2491665 - 2² = 2491661 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (2491661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7386 + ... + 7715.

It is an arithmetic number, because the mean of its divisors is an integer number (271836).

2^2491665 is an apocalyptic number.

It is an amenable number.

2491665 is a deficient number, since it is larger than the sum of its proper divisors (1857711).

2491665 is a wasteful number, since it uses less digits than its factorization.

2491665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15120.

The product of its digits is 12960, while the sum is 33.

The square root of 2491665 is about 1578.5008710799. The cubic root of 2491665 is about 135.5698817560.

The spelling of 2491665 in words is "two million, four hundred ninety-one thousand, six hundred sixty-five".