20371 has 4 divisors (see below), whose sum is σ = 21952. Its totient is φ = 18792.

The previous prime is 20369. The next prime is 20389. The reversal of 20371 is 17302.

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

It is a cyclic number.

It is not a de Polignac number, because 20371 - 2¹ = 20369 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1567 = 20371 / (2 + 0 + 3 + 7 + 1).

It is a Duffinian number.

20371 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (20341) 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, 771 + ... + 796.

It is an arithmetic number, because the mean of its divisors is an integer number (5488).

2²⁰³⁷¹ is an apocalyptic number.

20371 is a deficient number, since it is larger than the sum of its proper divisors (1581).

20371 is a wasteful number, since it uses less digits than its factorization.

20371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 20371 is about 142.7270121596. The cubic root of 20371 is about 27.3109904002.

Adding to 20371 its reverse (17302), we get a palindrome (37673).

The spelling of 20371 in words is "twenty thousand, three hundred seventy-one", and thus it is an iban number.