3999691 has 8 divisors (see below), whose sum is σ = 4086720. Its totient is φ = 3913728.

The previous prime is 3999683. The next prime is 3999703. The reversal of 3999691 is 1969993.

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 3999691 - 2³ = 3999683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3999661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15435 + ... + 15691.

It is an arithmetic number, because the mean of its divisors is an integer number (510840).

Almost surely, 2^3999691 is an apocalyptic number.

3999691 is a deficient number, since it is larger than the sum of its proper divisors (87029).

3999691 is a wasteful number, since it uses less digits than its factorization.

3999691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533.

The product of its digits is 118098, while the sum is 46.

The square root of 3999691 is about 1999.9227485081. The cubic root of 3999691 is about 158.7360175339.

The spelling of 3999691 in words is "three million, nine hundred ninety-nine thousand, six hundred ninety-one".