187993 has 4 divisors (see below), whose sum is σ = 202468. Its totient is φ = 173520.

The previous prime is 187987. The next prime is 188011. The reversal of 187993 is 399781.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17424 + 170569 = 132^2 + 413^2 .

It is a cyclic number.

It is not a de Polignac number, because 187993 - 2¹³ = 179801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (187963) 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, 7218 + ... + 7243.

It is an arithmetic number, because the mean of its divisors is an integer number (50617).

2¹⁸⁷⁹⁹³ is an apocalyptic number.

187993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

187993 is a deficient number, since it is larger than the sum of its proper divisors (14475).

187993 is a wasteful number, since it uses less digits than its factorization.

187993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14474.

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

The square root of 187993 is about 433.5815955504. The cubic root of 187993 is about 57.2858321478.

Adding to 187993 its product of digits (13608), we get a square (201601 = 449²).

The spelling of 187993 in words is "one hundred eighty-seven thousand, nine hundred ninety-three".