3999867 has 4 divisors (see below), whose sum is σ = 5333160. Its totient is φ = 2666576.

The previous prime is 3999859. The next prime is 3999871. The reversal of 3999867 is 7689993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7689993 = 3 ⋅2563331.

It is a cyclic number.

It is not a de Polignac number, because 3999867 - 2³ = 3999859 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (3999067) 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, 666642 + ... + 666647.

It is an arithmetic number, because the mean of its divisors is an integer number (1333290).

Almost surely, 2^3999867 is an apocalyptic number.

3999867 is a deficient number, since it is larger than the sum of its proper divisors (1333293).

3999867 is a wasteful number, since it uses less digits than its factorization.

3999867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333292.

The product of its digits is 734832, while the sum is 51.

The square root of 3999867 is about 1999.9667497236. The cubic root of 3999867 is about 158.7383458078.

It can be divided in two parts, 399986 and 7, that added together give a palindrome (399993).

The spelling of 3999867 in words is "three million, nine hundred ninety-nine thousand, eight hundred sixty-seven".