18937 has 4 divisors (see below), whose sum is σ = 19620. Its totient is φ = 18256.

The previous prime is 18919. The next prime is 18947. The reversal of 18937 is 73981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73981 = 167 ⋅443.

It can be written as a sum of positive squares in 2 ways, for example, as 7056 + 11881 = 84^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 18937 - 2¹¹ = 16889 is a prime.

It is a Duffinian number.

18937 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (18917) 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, 298 + ... + 355.

It is an arithmetic number, because the mean of its divisors is an integer number (4905).

2¹⁸⁹³⁷ is an apocalyptic number.

It is an amenable number.

18937 is a deficient number, since it is larger than the sum of its proper divisors (683).

18937 is an equidigital number, since it uses as much as digits as its factorization.

18937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682.

The product of its digits is 1512, while the sum is 28.

The square root of 18937 is about 137.6117727522. The cubic root of 18937 is about 26.6544909693.

Adding to 18937 its product of digits (1512), we get a square (20449 = 143²).

The spelling of 18937 in words is "eighteen thousand, nine hundred thirty-seven".