20001851 has 16 divisors (see below), whose sum is σ = 22502400. Its totient is φ = 17690400.

The previous prime is 20001847. The next prime is 20001853. The reversal of 20001851 is 15810002.

It is a cyclic number.

It is not a de Polignac number, because 20001851 - 2² = 20001847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20001853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16496 + ... + 17666.

It is an arithmetic number, because the mean of its divisors is an integer number (1406400).

Almost surely, 2^20001851 is an apocalyptic number.

20001851 is a deficient number, since it is larger than the sum of its proper divisors (2500549).

20001851 is a wasteful number, since it uses less digits than its factorization.

20001851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1250.

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

The square root of 20001851 is about 4472.3428983029. The cubic root of 20001851 is about 271.4501353795.

Adding to 20001851 its reverse (15810002), we get a palindrome (35811853).

The spelling of 20001851 in words is "twenty million, one thousand, eight hundred fifty-one".