158391 has 6 divisors (see below), whose sum is σ = 228800. Its totient is φ = 105588.

The previous prime is 158371. The next prime is 158393. The reversal of 158391 is 193851.

It is not a de Polignac number, because 158391 - 2⁵ = 158359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 158391.

It is not an unprimeable number, because it can be changed into a prime (158393) 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 5 ways as a sum of consecutive naturals, for example, 8791 + ... + 8808.

2¹⁵⁸³⁹¹ is an apocalyptic number.

158391 is a deficient number, since it is larger than the sum of its proper divisors (70409).

158391 is a wasteful number, since it uses less digits than its factorization.

158391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17605 (or 17602 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 158391 is about 397.9836680066. The cubic root of 158391 is about 54.1057598108.

The spelling of 158391 in words is "one hundred fifty-eight thousand, three hundred ninety-one".