20938 has 12 divisors (see below), whose sum is σ = 34290. Its totient is φ = 9576.

The previous prime is 20929. The next prime is 20939. The reversal of 20938 is 83902.

It can be written as a sum of positive squares in only one way, i.e., 17689 + 3249 = 133^2 + 57^2 .

It is not an unprimeable number, because it can be changed into a prime (20939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 708 + ... + 736.

2²⁰⁹³⁸ is an apocalyptic number.

20938 is a deficient number, since it is larger than the sum of its proper divisors (13352).

20938 is a wasteful number, since it uses less digits than its factorization.

20938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20938 is about 144.6996890114. The cubic root of 20938 is about 27.5620636823.

The spelling of 20938 in words is "twenty thousand, nine hundred thirty-eight".