3861999 has 24 divisors (see below), whose sum is σ = 6045312. Its totient is φ = 2459160.

The previous prime is 3861989. The next prime is 3862003. The reversal of 3861999 is 9991683.

It is not a de Polignac number, because 3861999 - 2⁴ = 3861983 is a prime.

Its product of digits (104976) is a multiple of the sum of its prime factors (729).

3861999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3861929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5244 + ... + 5934.

It is an arithmetic number, because the mean of its divisors is an integer number (251888).

Almost surely, 2^3861999 is an apocalyptic number.

3861999 is a deficient number, since it is larger than the sum of its proper divisors (2183313).

3861999 is an equidigital number, since it uses as much as digits as its factorization.

3861999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729 (or 717 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 3861999 is about 1965.1969366962. The cubic root of 3861999 is about 156.8931751982.

The spelling of 3861999 in words is "three million, eight hundred sixty-one thousand, nine hundred ninety-nine".