181387 has 2 divisors, whose sum is σ = 181388. Its totient is φ = 181386.

The previous prime is 181361. The next prime is 181397. The reversal of 181387 is 783181.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181387 is a prime.

It is not a weakly prime, because it can be changed into another prime (181397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90693 + 90694.

It is an arithmetic number, because the mean of its divisors is an integer number (90694).

2¹⁸¹³⁸⁷ is an apocalyptic number.

181387 is a deficient number, since it is larger than the sum of its proper divisors (1).

181387 is an equidigital number, since it uses as much as digits as its factorization.

181387 is an evil number, because the sum of its binary digits is even.

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

The square root of 181387 is about 425.8955270956. The cubic root of 181387 is about 56.6068149302.

It can be divided in two parts, 18138 and 7, that added together give a triangular number (18145 = T₁₉₀).

The spelling of 181387 in words is "one hundred eighty-one thousand, three hundred eighty-seven".