20139 has 12 divisors (see below), whose sum is σ = 31464. Its totient is φ = 11424.

The previous prime is 20129. The next prime is 20143. The reversal of 20139 is 93102.

It is not a de Polignac number, because 20139 - 2⁴ = 20123 is a prime.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (20129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79 + ... + 215.

It is an arithmetic number, because the mean of its divisors is an integer number (2622).

2²⁰¹³⁹ is an apocalyptic number.

20139 is a deficient number, since it is larger than the sum of its proper divisors (11325).

20139 is a wasteful number, since it uses less digits than its factorization.

20139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 20139 is about 141.9119445290. The cubic root of 20139 is about 27.2069150527.

The spelling of 20139 in words is "twenty thousand, one hundred thirty-nine".