1158987 has 4 divisors (see below), whose sum is σ = 1545320. Its totient is φ = 772656.

The previous prime is 1158977. The next prime is 1158991. The reversal of 1158987 is 7898511.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1158987 - 2⁶ = 1158923 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1158977) 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, 193162 + ... + 193167.

It is an arithmetic number, because the mean of its divisors is an integer number (386330).

2^1158987 is an apocalyptic number.

1158987 is a deficient number, since it is larger than the sum of its proper divisors (386333).

1158987 is an equidigital number, since it uses as much as digits as its factorization.

1158987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386332.

The product of its digits is 20160, while the sum is 39.

The square root of 1158987 is about 1076.5625852685. The cubic root of 1158987 is about 105.0411629991.

It can be divided in two parts, 1158 and 987, that added together give a triangular number (2145 = T₆₅).

The spelling of 1158987 in words is "one million, one hundred fifty-eight thousand, nine hundred eighty-seven".