187121 has 4 divisors (see below), whose sum is σ = 204144. Its totient is φ = 170100.

The previous prime is 187111. The next prime is 187123. The reversal of 187121 is 121781.

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, and also an emirpimes, since its reverse is a distinct semiprime: 121781 = 11 ⋅11071.

It is a cyclic number.

It is not a de Polignac number, because 187121 - 2¹⁰ = 186097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 187093 and 187102.

It is not an unprimeable number, because it can be changed into a prime (187123) 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, 8495 + ... + 8516.

It is an arithmetic number, because the mean of its divisors is an integer number (51036).

2¹⁸⁷¹²¹ is an apocalyptic number.

187121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

187121 is a deficient number, since it is larger than the sum of its proper divisors (17023).

187121 is a wasteful number, since it uses less digits than its factorization.

187121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17022.

The product of its digits is 112, while the sum is 20.

The square root of 187121 is about 432.5748490146. The cubic root of 187121 is about 57.1971219639.

The spelling of 187121 in words is "one hundred eighty-seven thousand, one hundred twenty-one".