20738 has 4 divisors (see below), whose sum is σ = 31110. Its totient is φ = 10368.

The previous prime is 20731. The next prime is 20743. The reversal of 20738 is 83702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83702 = 2 ⋅41851.

It can be written as a sum of positive squares in only one way, i.e., 20449 + 289 = 143^2 + 17^2 .

It is not an unprimeable number, because it can be changed into a prime (20731) by changing a digit.

20738 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 as a sum of consecutive naturals, namely, 5183 + ... + 5186.

2²⁰⁷³⁸ is an apocalyptic number.

20738 is a deficient number, since it is larger than the sum of its proper divisors (10372).

20738 is a wasteful number, since it uses less digits than its factorization.

20738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10371.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 20738 is about 144.0069442770. The cubic root of 20738 is about 27.4740250600.

Subtracting from 20738 its product of nonzero digits (336), we obtain a palindrome (20402).

The spelling of 20738 in words is "twenty thousand, seven hundred thirty-eight".