3991099 has 12 divisors (see below), whose sum is σ = 4744224. Its totient is φ = 3346224.

The previous prime is 3991093. The next prime is 3991103. The reversal of 3991099 is 9901993.

It is not a de Polignac number, because 3991099 - 2¹⁹ = 3466811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3991093) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1437 + ... + 3169.

It is an arithmetic number, because the mean of its divisors is an integer number (395352).

Almost surely, 2^3991099 is an apocalyptic number.

3991099 is a deficient number, since it is larger than the sum of its proper divisors (753125).

3991099 is a wasteful number, since it uses less digits than its factorization.

3991099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794 (or 1787 counting only the distinct ones).

The product of its (nonzero) digits is 19683, while the sum is 40.

The square root of 3991099 is about 1997.7735106863. The cubic root of 3991099 is about 158.6222722780.

The spelling of 3991099 in words is "three million, nine hundred ninety-one thousand, ninety-nine".