3999399 has 4 divisors (see below), whose sum is σ = 5332536. Its totient is φ = 2666264.

The previous prime is 3999389. The next prime is 3999421. The reversal of 3999399 is 9939993.

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 3999399 - 2⁴ = 3999383 is a prime.

It is a super-2 number, since 2×3999399² = 31990384722402, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3999379) 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, 666564 + ... + 666569.

It is an arithmetic number, because the mean of its divisors is an integer number (1333134).

Almost surely, 2^3999399 is an apocalyptic number.

3999399 is a deficient number, since it is larger than the sum of its proper divisors (1333137).

3999399 is a wasteful number, since it uses less digits than its factorization.

3999399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333136.

The product of its digits is 531441, while the sum is 51.

The square root of 3999399 is about 1999.8497443558. The cubic root of 3999399 is about 158.7321545650.

The spelling of 3999399 in words is "three million, nine hundred ninety-nine thousand, three hundred ninety-nine".