3999001 has 2 divisors, whose sum is σ = 3999002. Its totient is φ = 3999000.

The previous prime is 3998999. The next prime is 3999053. The reversal of 3999001 is 1009993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3667225 + 331776 = 1915^2 + 576^2 .

It is an emirp because it is prime and its reverse (1009993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3999001 - 2¹ = 3998999 is a prime.

Together with 3998999, it forms a pair of twin primes.

3999001 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3999901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999500 + 1999501.

It is an arithmetic number, because the mean of its divisors is an integer number (1999501).

Almost surely, 2^3999001 is an apocalyptic number.

It is an amenable number.

3999001 is a deficient number, since it is larger than the sum of its proper divisors (1).

3999001 is an equidigital number, since it uses as much as digits as its factorization.

3999001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 3999001 is about 1999.7502344043. The cubic root of 3999001 is about 158.7268889828.

The spelling of 3999001 in words is "three million, nine hundred ninety-nine thousand, one".