3999217 has 16 divisors (see below), whose sum is σ = 4423680. Its totient is φ = 3603600.

The previous prime is 3999211. The next prime is 3999239. The reversal of 3999217 is 7129993.

It is a cyclic number.

It is not a de Polignac number, because 3999217 - 2³ = 3999209 is a prime.

It is a super-2 number, since 2×3999217² = 31987473226178, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3999217.

It is not an unprimeable number, because it can be changed into a prime (3999211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50584 + ... + 50662.

It is an arithmetic number, because the mean of its divisors is an integer number (276480).

Almost surely, 2^3999217 is an apocalyptic number.

3999217 is the 1633-rd pentagonal number.

It is an amenable number.

3999217 is a deficient number, since it is larger than the sum of its proper divisors (424463).

3999217 is a wasteful number, since it uses less digits than its factorization.

3999217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204.

The product of its digits is 30618, while the sum is 40.

The square root of 3999217 is about 1999.8042404195. The cubic root of 3999217 is about 158.7297467290.

The spelling of 3999217 in words is "three million, nine hundred ninety-nine thousand, two hundred seventeen".