2091647 has 4 divisors (see below), whose sum is σ = 2148216. Its totient is φ = 2035080.

The previous prime is 2091637. The next prime is 2091659. The reversal of 2091647 is 7461902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2091647 - 2⁴ = 2091631 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 (2091637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28229 + ... + 28302.

It is an arithmetic number, because the mean of its divisors is an integer number (537054).

2^2091647 is an apocalyptic number.

2091647 is a deficient number, since it is larger than the sum of its proper divisors (56569).

2091647 is an equidigital number, since it uses as much as digits as its factorization.

2091647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56568.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 2091647 is about 1446.2527441633. The cubic root of 2091647 is about 127.8879023460.

The spelling of 2091647 in words is "two million, ninety-one thousand, six hundred forty-seven".