3866209 has 4 divisors (see below), whose sum is σ = 3870720. Its totient is φ = 3861700.

The previous prime is 3866201. The next prime is 3866237. The reversal of 3866209 is 9026683.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9026683 = 41 ⋅220163.

It is a cyclic number.

It is not a de Polignac number, because 3866209 - 2³ = 3866201 is a prime.

It is a Duffinian number.

3866209 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3866201) 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, 529 + ... + 2830.

It is an arithmetic number, because the mean of its divisors is an integer number (967680).

Almost surely, 2^3866209 is an apocalyptic number.

It is an amenable number.

3866209 is a deficient number, since it is larger than the sum of its proper divisors (4511).

3866209 is a wasteful number, since it uses less digits than its factorization.

3866209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4510.

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

The square root of 3866209 is about 1966.2677844078. The cubic root of 3866209 is about 156.9501647176.

The spelling of 3866209 in words is "three million, eight hundred sixty-six thousand, two hundred nine".