158189987 has 4 divisors (see below), whose sum is σ = 158328576. Its totient is φ = 158051400.

The previous prime is 158189971. The next prime is 158190047. The reversal of 158189987 is 789981851.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789981851 = 23 ⋅34347037.

It is a cyclic number.

It is not a de Polignac number, because 158189987 - 2⁴ = 158189971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (158189957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67568 + ... + 69869.

It is an arithmetic number, because the mean of its divisors is an integer number (39582144).

Almost surely, 2^158189987 is an apocalyptic number.

158189987 is a deficient number, since it is larger than the sum of its proper divisors (138589).

158189987 is a wasteful number, since it uses less digits than its factorization.

158189987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138588.

The product of its digits is 1451520, while the sum is 56.

The square root of 158189987 is about 12577.3600966180. The cubic root of 158189987 is about 540.8286169744.

The spelling of 158189987 in words is "one hundred fifty-eight million, one hundred eighty-nine thousand, nine hundred eighty-seven".