1812001 has 4 divisors (see below), whose sum is σ = 1861012. Its totient is φ = 1762992.

The previous prime is 1811993. The next prime is 1812037. The reversal of 1812001 is 1002181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1002181 = 47 ⋅21323.

It can be written as a sum of positive squares in 2 ways, for example, as 810000 + 1002001 = 900^2 + 1001^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812001 - 2³ = 1811993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1812061) 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, 24450 + ... + 24523.

It is an arithmetic number, because the mean of its divisors is an integer number (465253).

2^1812001 is an apocalyptic number.

It is an amenable number.

1812001 is a deficient number, since it is larger than the sum of its proper divisors (49011).

1812001 is an equidigital number, since it uses as much as digits as its factorization.

1812001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49010.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1812001 is about 1346.1058650790. The cubic root of 1812001 is about 121.9137839310.

Adding to 1812001 its reverse (1002181), we get a palindrome (2814182).

The spelling of 1812001 in words is "one million, eight hundred twelve thousand, one".