3966399 has 6 divisors (see below), whose sum is σ = 5729256. Its totient is φ = 2644260.

The previous prime is 3966349. The next prime is 3966407. The reversal of 3966399 is 9936693.

3966399 is a `hidden beast` number, since 3 + 9 + 6 + 639 + 9 = 666.

It is not a de Polignac number, because 3966399 - 2⁷ = 3966271 is a prime.

3966399 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3966329) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 220347 + ... + 220364.

It is an arithmetic number, because the mean of its divisors is an integer number (954876).

Almost surely, 2^3966399 is an apocalyptic number.

3966399 is a deficient number, since it is larger than the sum of its proper divisors (1762857).

3966399 is a wasteful number, since it uses less digits than its factorization.

3966399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440717 (or 440714 counting only the distinct ones).

The product of its digits is 236196, while the sum is 45.

The square root of 3966399 is about 1991.5820344641. The cubic root of 3966399 is about 158.2943692364.

The spelling of 3966399 in words is "three million, nine hundred sixty-six thousand, three hundred ninety-nine".