20031 has 8 divisors (see below), whose sum is σ = 29184. Its totient is φ = 12120.

The previous prime is 20029. The next prime is 20047. The reversal of 20031 is 13002.

20031 = 19² + 20² + ... + 40².

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20031 - 2¹ = 20029 is a prime.

It is a super-2 number, since 2×20031² = 802481922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271 + ... + 336.

It is an arithmetic number, because the mean of its divisors is an integer number (3648).

2²⁰⁰³¹ is an apocalyptic number.

20031 is a deficient number, since it is larger than the sum of its proper divisors (9153).

20031 is a wasteful number, since it uses less digits than its factorization.

20031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621.

The product of its (nonzero) digits is 6, while the sum is 6.

The square root of 20031 is about 141.5309153507. The cubic root of 20031 is about 27.1581934172.

Adding to 20031 its reverse (13002), we get a palindrome (33033).

It can be divided in two parts, 200 and 31, that added together give a triangular number (231 = T₂₁).

The spelling of 20031 in words is "twenty thousand, thirty-one".