87391 has 4 divisors (see below), whose sum is σ = 87984. Its totient is φ = 86800.

The previous prime is 87383. The next prime is 87403. The reversal of 87391 is 19378.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19378 = 2 ⋅9689.

It is a cyclic number.

It is not a de Polignac number, because 87391 - 2³ = 87383 is a prime.

It is a Duffinian number.

87391 is a lucky number.

It is a plaindrome in base 4 and base 16.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87491) 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, 126 + ... + 436.

It is an arithmetic number, because the mean of its divisors is an integer number (21996).

2⁸⁷³⁹¹ is an apocalyptic number.

87391 is a deficient number, since it is larger than the sum of its proper divisors (593).

87391 is a wasteful number, since it uses less digits than its factorization.

87391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592.

The product of its digits is 1512, while the sum is 28.

The square root of 87391 is about 295.6196881130. The cubic root of 87391 is about 44.3767578488.

The spelling of 87391 in words is "eighty-seven thousand, three hundred ninety-one".