2166779 has 4 divisors (see below), whose sum is σ = 2280840. Its totient is φ = 2052720.

The previous prime is 2166763. The next prime is 2166797. The reversal of 2166779 is 9776612.

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 2166779 - 2⁴ = 2166763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2166709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57002 + ... + 57039.

It is an arithmetic number, because the mean of its divisors is an integer number (570210).

2^2166779 is an apocalyptic number.

2166779 is a deficient number, since it is larger than the sum of its proper divisors (114061).

2166779 is a wasteful number, since it uses less digits than its factorization.

2166779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114060.

The product of its digits is 31752, while the sum is 38.

The square root of 2166779 is about 1471.9983016295. The cubic root of 2166779 is about 129.4011708513.

The spelling of 2166779 in words is "two million, one hundred sixty-six thousand, seven hundred seventy-nine".