187990 has 16 divisors (see below), whose sum is σ = 369360. Its totient is φ = 68320.

The previous prime is 187987. The next prime is 188011. The reversal of 187990 is 99781.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 745 + ... + 964.

It is an arithmetic number, because the mean of its divisors is an integer number (23085).

2¹⁸⁷⁹⁹⁰ is an apocalyptic number.

187990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

187990 is a deficient number, since it is larger than the sum of its proper divisors (181370).

187990 is a wasteful number, since it uses less digits than its factorization.

187990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1727.

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 187990 is about 433.5781359801. The cubic root of 187990 is about 57.2855274230.

Subtracting from 187990 its reverse (99781), we obtain a square (88209 = 297²).

It can be divided in two parts, 18 and 7990, that added together give a palindrome (8008).

The spelling of 187990 in words is "one hundred eighty-seven thousand, nine hundred ninety".