20051 has 2 divisors, whose sum is σ = 20052. Its totient is φ = 20050.

The previous prime is 20047. The next prime is 20063. The reversal of 20051 is 15002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20051 - 2² = 20047 is a prime.

It is a Chen prime.

It is a nialpdrome in base 14.

It is not a weakly prime, because it can be changed into another prime (20011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10025 + 10026.

It is an arithmetic number, because the mean of its divisors is an integer number (10026).

2²⁰⁰⁵¹ is an apocalyptic number.

20051 is a deficient number, since it is larger than the sum of its proper divisors (1).

20051 is an equidigital number, since it uses as much as digits as its factorization.

20051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 20051 is about 141.6015536638. The cubic root of 20051 is about 27.1672291318.

Adding to 20051 its reverse (15002), we get a palindrome (35053).

The spelling of 20051 in words is "twenty thousand, fifty-one".