20137 has 4 divisors (see below), whose sum is σ = 21700. Its totient is φ = 18576.

The previous prime is 20129. The next prime is 20143. The reversal of 20137 is 73102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73102 = 2 ⋅36551.

It can be written as a sum of positive squares in 2 ways, for example, as 4761 + 15376 = 69^2 + 124^2 .

It is a cyclic number.

It is not a de Polignac number, because 20137 - 2³ = 20129 is a prime.

It is a super-5 number, since 5×20137⁵ (a number of 23 digits) contains 55555 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1549 = 20137 / (2 + 0 + 1 + 3 + 7).

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 762 + ... + 787.

It is an arithmetic number, because the mean of its divisors is an integer number (5425).

2²⁰¹³⁷ is an apocalyptic number.

It is an amenable number.

20137 is a deficient number, since it is larger than the sum of its proper divisors (1563).

20137 is a wasteful number, since it uses less digits than its factorization.

20137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 20137 is about 141.9048977308. The cubic root of 20137 is about 27.2060143851.

Adding to 20137 its reverse (73102), we get a palindrome (93239).

The spelling of 20137 in words is "twenty thousand, one hundred thirty-seven".