3999789 has 6 divisors (see below), whose sum is σ = 5777486. Its totient is φ = 2666520.

The previous prime is 3999781. The next prime is 3999791. The reversal of 3999789 is 9879993.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3674889 + 324900 = 1917^2 + 570^2 .

It is not a de Polignac number, because 3999789 - 2³ = 3999781 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 (3999781) 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, 222202 + ... + 222219.

Almost surely, 2^3999789 is an apocalyptic number.

It is an amenable number.

3999789 is a deficient number, since it is larger than the sum of its proper divisors (1777697).

3999789 is a wasteful number, since it uses less digits than its factorization.

3999789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444427 (or 444424 counting only the distinct ones).

The product of its digits is 1102248, while the sum is 54.

The square root of 3999789 is about 1999.9472493043. The cubic root of 3999789 is about 158.7373139676.

The spelling of 3999789 in words is "three million, nine hundred ninety-nine thousand, seven hundred eighty-nine".