2166774209 has 4 divisors (see below), whose sum is σ = 2185949316. Its totient is φ = 2147599104.

The previous prime is 2166774173. The next prime is 2166774283. The reversal of 2166774209 is 9024776612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 454883584 + 1711890625 = 21328^2 + 41375^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166774209 - 2¹² = 2166770113 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2166774209.

It is not an unprimeable number, because it can be changed into a prime (2166773209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9587384 + ... + 9587609.

It is an arithmetic number, because the mean of its divisors is an integer number (546487329).

Almost surely, 2^2166774209 is an apocalyptic number.

It is an amenable number.

2166774209 is a deficient number, since it is larger than the sum of its proper divisors (19175107).

2166774209 is a wasteful number, since it uses less digits than its factorization.

2166774209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19175106.

The product of its (nonzero) digits is 254016, while the sum is 44.

The square root of 2166774209 is about 46548.6219881964. The cubic root of 2166774209 is about 1294.0107547757.

The spelling of 2166774209 in words is "two billion, one hundred sixty-six million, seven hundred seventy-four thousand, two hundred nine".