20438 has 8 divisors (see below), whose sum is σ = 33480. Its totient is φ = 9280.

The previous prime is 20431. The next prime is 20441. The reversal of 20438 is 83402.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431) by changing a digit.

20438 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443 + ... + 486.

It is an arithmetic number, because the mean of its divisors is an integer number (4185).

2²⁰⁴³⁸ is an apocalyptic number.

20438 is a deficient number, since it is larger than the sum of its proper divisors (13042).

20438 is a wasteful number, since it uses less digits than its factorization.

20438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 20438 is about 142.9615332878. The cubic root of 20438 is about 27.3408994852.

It can be divided in two parts, 204 and 38, that added together give a palindrome (242).

The spelling of 20438 in words is "twenty thousand, four hundred thirty-eight".