3997999 has 4 divisors (see below), whose sum is σ = 4208440. Its totient is φ = 3787560.

The previous prime is 3997997. The next prime is 3998003. The reversal of 3997999 is 9997993.

3997999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9997993 = 89 ⋅112337.

It is a cyclic number.

It is not a de Polignac number, because 3997999 - 2¹ = 3997997 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3997993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105192 + ... + 105229.

It is an arithmetic number, because the mean of its divisors is an integer number (1052110).

Almost surely, 2^3997999 is an apocalyptic number.

3997999 is a deficient number, since it is larger than the sum of its proper divisors (210441).

3997999 is a wasteful number, since it uses less digits than its factorization.

3997999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210440.

The product of its digits is 1240029, while the sum is 55.

The square root of 3997999 is about 1999.4996874218. The cubic root of 3997999 is about 158.7136308692.

It can be divided in two parts, 399 and 7999, that multiplied together give a triangular number (3191601 = T₂₅₂₆).

The spelling of 3997999 in words is "three million, nine hundred ninety-seven thousand, nine hundred ninety-nine".