3999989999 has 4 divisors (see below), whose sum is σ = 4013642136. Its totient is φ = 3986337864.

The previous prime is 3999989957. The next prime is 3999990011. The reversal of 3999989999 is 9999899993.

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 3999989999 - 2⁸ = 3999989743 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 (3999989909) 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, 6825629 + ... + 6826214.

It is an arithmetic number, because the mean of its divisors is an integer number (1003410534).

Almost surely, 2^3999989999 is an apocalyptic number.

3999989999 is a deficient number, since it is larger than the sum of its proper divisors (13652137).

3999989999 is a wasteful number, since it uses less digits than its factorization.

3999989999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13652136.

The product of its digits is 1033121304, while the sum is 83.

The square root of 3999989999 is about 63245.4741384710. The cubic root of 3999989999 is about 1587.3997290006.

The spelling of 3999989999 in words is "three billion, nine hundred ninety-nine million, nine hundred eighty-nine thousand, nine hundred ninety-nine".