2166506 has 4 divisors (see below), whose sum is σ = 3249762. Its totient is φ = 1083252.

The previous prime is 2166467. The next prime is 2166509. The reversal of 2166506 is 6056612.

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

It can be written as a sum of positive squares in only one way, i.e., 1755625 + 410881 = 1325^2 + 641^2 .

It is not an unprimeable number, because it can be changed into a prime (2166509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 541625 + ... + 541628.

2^2166506 is an apocalyptic number.

2166506 is a deficient number, since it is larger than the sum of its proper divisors (1083256).

2166506 is a wasteful number, since it uses less digits than its factorization.

2166506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1083255.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 2166506 is about 1471.9055676231. The cubic root of 2166506 is about 129.3957360556.

The spelling of 2166506 in words is "two million, one hundred sixty-six thousand, five hundred six".