1999001 has 4 divisors (see below), whose sum is σ = 2036772. Its totient is φ = 1961232.

The previous prime is 1998991. The next prime is 1999007. The reversal of 1999001 is 1009991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1795600 + 203401 = 1340^2 + 451^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999001 is a prime.

It is a pancake number, because a pancake can be divided into 1999001 parts by 1999 straight cuts.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1999007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18806 + ... + 18911.

It is an arithmetic number, because the mean of its divisors is an integer number (509193).

2^1999001 is an apocalyptic number.

It is an amenable number.

1999001 is a deficient number, since it is larger than the sum of its proper divisors (37771).

1999001 is an equidigital number, since it uses as much as digits as its factorization.

1999001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37770.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 1999001 is about 1413.8603184190. The cubic root of 1999001 is about 125.9711238103.

The spelling of 1999001 in words is "one million, nine hundred ninety-nine thousand, one".