4005865 has 16 divisors (see below), whose sum is σ = 5112000. Its totient is φ = 3004992.

The previous prime is 4005847. The next prime is 4005889. The reversal of 4005865 is 5685004.

4005865 is a nontrivial binomial coefficient, being equal to C(2831, 2).

It is a cyclic number.

It is not a de Polignac number, because 4005865 - 2¹³ = 3997673 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14014 + ... + 14296.

It is an arithmetic number, because the mean of its divisors is an integer number (319500).

Almost surely, 2^4005865 is an apocalyptic number.

4005865 is the 2830-th triangular number.

4005865 is the 944-th centered nonagonal number.

It is an amenable number.

4005865 is a deficient number, since it is larger than the sum of its proper divisors (1106135).

4005865 is a wasteful number, since it uses less digits than its factorization.

4005865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 4005865 is about 2001.4657129214. The cubic root of 4005865 is about 158.8176515348.

The spelling of 4005865 in words is "four million, five thousand, eight hundred sixty-five".