3971999 has 8 divisors (see below), whose sum is σ = 4341888. Its totient is φ = 3617280.

The previous prime is 3971993. The next prime is 3972011. The reversal of 3971999 is 9991793.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3971999 - 2⁴ = 3971983 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 (3971993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3242 + ... + 4295.

It is an arithmetic number, because the mean of its divisors is an integer number (542736).

Almost surely, 2^3971999 is an apocalyptic number.

3971999 is a deficient number, since it is larger than the sum of its proper divisors (369889).

3971999 is a wasteful number, since it uses less digits than its factorization.

3971999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7585.

The product of its digits is 137781, while the sum is 47.

The square root of 3971999 is about 1992.9874560569. The cubic root of 3971999 is about 158.3688306992.

The spelling of 3971999 in words is "three million, nine hundred seventy-one thousand, nine hundred ninety-nine".