1171987 has 4 divisors (see below), whose sum is σ = 1176496. Its totient is φ = 1167480.

The previous prime is 1171981. The next prime is 1171991. The reversal of 1171987 is 7891711.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7891711 = 2423 ⋅3257.

It is a cyclic number.

It is not a de Polignac number, because 1171987 - 2³ = 1171979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1171981) 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, 1839 + ... + 2392.

It is an arithmetic number, because the mean of its divisors is an integer number (294124).

2^1171987 is an apocalyptic number.

1171987 is a deficient number, since it is larger than the sum of its proper divisors (4509).

1171987 is an equidigital number, since it uses as much as digits as its factorization.

1171987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4508.

The product of its digits is 3528, while the sum is 34.

The square root of 1171987 is about 1082.5834840787. The cubic root of 1171987 is about 105.4324417920.

The spelling of 1171987 in words is "one million, one hundred seventy-one thousand, nine hundred eighty-seven".