187381 has 4 divisors (see below), whose sum is σ = 195552. Its totient is φ = 179212.

The previous prime is 187379. The next prime is 187387. The reversal of 187381 is 183781.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 187381 - 2¹ = 187379 is a prime.

It is a super-2 number, since 2×187381² = 70223278322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (187387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4051 + ... + 4096.

It is an arithmetic number, because the mean of its divisors is an integer number (48888).

2¹⁸⁷³⁸¹ is an apocalyptic number.

It is an amenable number.

187381 is a deficient number, since it is larger than the sum of its proper divisors (8171).

187381 is an equidigital number, since it uses as much as digits as its factorization.

187381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8170.

The product of its digits is 1344, while the sum is 28.

The square root of 187381 is about 432.8752707189. The cubic root of 187381 is about 57.2236010323.

Subtracting from 187381 its reverse (183781), we obtain a square (3600 = 60²).

The spelling of 187381 in words is "one hundred eighty-seven thousand, three hundred eighty-one".