2166649 has 4 divisors (see below), whose sum is σ = 2172240. Its totient is φ = 2161060.

The previous prime is 2166629. The next prime is 2166673. The reversal of 2166649 is 9466612.

2166649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2166649 - 2⁹ = 2166137 is a prime.

It is a Duffinian number.

2166649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2166629) 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 3 ways as a sum of consecutive naturals, for example, 2167 + ... + 3004.

It is an arithmetic number, because the mean of its divisors is an integer number (543060).

2^2166649 is an apocalyptic number.

It is an amenable number.

2166649 is a deficient number, since it is larger than the sum of its proper divisors (5591).

2166649 is an equidigital number, since it uses as much as digits as its factorization.

2166649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5590.

The product of its digits is 15552, while the sum is 34.

The square root of 2166649 is about 1471.9541433075. The cubic root of 2166649 is about 129.3985829103.

The spelling of 2166649 in words is "two million, one hundred sixty-six thousand, six hundred forty-nine".