2001851 has 4 divisors (see below), whose sum is σ = 2088912. Its totient is φ = 1914792.

The previous prime is 2001847. The next prime is 2001911. The reversal of 2001851 is 1581002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1581002 = 2 ⋅790501.

It is a cyclic number.

It is not a de Polignac number, because 2001851 - 2² = 2001847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001451) 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, 43496 + ... + 43541.

It is an arithmetic number, because the mean of its divisors is an integer number (522228).

2^2001851 is an apocalyptic number.

2001851 is a deficient number, since it is larger than the sum of its proper divisors (87061).

2001851 is an equidigital number, since it uses as much as digits as its factorization.

2001851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87060.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 2001851 is about 1414.8678383510. The cubic root of 2001851 is about 126.0309615691.

Adding to 2001851 its reverse (1581002), we get a palindrome (3582853).

The spelling of 2001851 in words is "two million, one thousand, eight hundred fifty-one".