3865999 has 4 divisors (see below), whose sum is σ = 3871864. Its totient is φ = 3860136.

The previous prime is 3865993. The next prime is 3866011. The reversal of 3865999 is 9995683.

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 3865999 - 2³ = 3865991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3865991) 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, 1797 + ... + 3310.

It is an arithmetic number, because the mean of its divisors is an integer number (967966).

Almost surely, 2^3865999 is an apocalyptic number.

3865999 is a deficient number, since it is larger than the sum of its proper divisors (5865).

3865999 is an equidigital number, since it uses as much as digits as its factorization.

3865999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5864.

The product of its digits is 524880, while the sum is 49.

The square root of 3865999 is about 1966.2143830213. The cubic root of 3865999 is about 156.9473229906.

The spelling of 3865999 in words is "three million, eight hundred sixty-five thousand, nine hundred ninety-nine".