193987 has 4 divisors (see below), whose sum is σ = 205416. Its totient is φ = 182560.

The previous prime is 193979. The next prime is 193993. The reversal of 193987 is 789391.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 193987 - 2³ = 193979 is a prime.

It is a Duffinian number.

193987 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (193937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5689 + ... + 5722.

It is an arithmetic number, because the mean of its divisors is an integer number (51354).

2¹⁹³⁹⁸⁷ is an apocalyptic number.

193987 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

193987 is a deficient number, since it is larger than the sum of its proper divisors (11429).

193987 is a wasteful number, since it uses less digits than its factorization.

193987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11428.

The product of its digits is 13608, while the sum is 37.

The square root of 193987 is about 440.4395531739. The cubic root of 193987 is about 57.8883106250. Note that the first 3 decimals are identical.

The spelling of 193987 in words is "one hundred ninety-three thousand, nine hundred eighty-seven".