187421 has 6 divisors (see below), whose sum is σ = 203130. Its totient is φ = 172848.

The previous prime is 187417. The next prime is 187423. The reversal of 187421 is 124781.

It can be written as a sum of positive squares in 3 ways, for example, as 19321 + 168100 = 139^2 + 410^2 .

It is not a de Polignac number, because 187421 - 2² = 187417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (187423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 386 + ... + 723.

It is an arithmetic number, because the mean of its divisors is an integer number (33855).

2¹⁸⁷⁴²¹ is an apocalyptic number.

It is an amenable number.

187421 is a deficient number, since it is larger than the sum of its proper divisors (15709).

187421 is a wasteful number, since it uses less digits than its factorization.

187421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135 (or 1122 counting only the distinct ones).

The product of its digits is 448, while the sum is 23.

The square root of 187421 is about 432.9214709390. The cubic root of 187421 is about 57.2276725607.

The spelling of 187421 in words is "one hundred eighty-seven thousand, four hundred twenty-one".