3998001 has 16 divisors (see below), whose sum is σ = 6194048. Its totient is φ = 2246400.

The previous prime is 3997997. The next prime is 3998003. The reversal of 3998001 is 1008993.

It is a happy number.

It is not a de Polignac number, because 3998001 - 2² = 3997997 is a prime.

It is the 2000-th Hogben number.

It is a self number, because there is not a number n which added to its sum of digits gives 3998001.

It is not an unprimeable number, because it can be changed into a prime (3998003) by changing a digit.

It is a nontrivial repunit in base 1999.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280 + ... + 2841.

It is an arithmetic number, because the mean of its divisors is an integer number (387128).

Almost surely, 2^3998001 is an apocalyptic number.

It is an amenable number.

3998001 is a deficient number, since it is larger than the sum of its proper divisors (2196047).

3998001 is a wasteful number, since it uses less digits than its factorization.

3998001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3192.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 3998001 is about 1999.5001875469. The cubic root of 3998001 is about 158.7136573347.

The spelling of 3998001 in words is "three million, nine hundred ninety-eight thousand, one".