1091987 has 8 divisors (see below), whose sum is σ = 1238160. Its totient is φ = 954720.

The previous prime is 1091983. The next prime is 1092019. The reversal of 1091987 is 7891901.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1091987 - 2² = 1091983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1091983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1964 + ... + 2457.

It is an arithmetic number, because the mean of its divisors is an integer number (154770).

2^1091987 is an apocalyptic number.

1091987 is a deficient number, since it is larger than the sum of its proper divisors (146173).

1091987 is a wasteful number, since it uses less digits than its factorization.

1091987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4453.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 1091987 is about 1044.9818180236. The cubic root of 1091987 is about 102.9767440504.

The spelling of 1091987 in words is "one million, ninety-one thousand, nine hundred eighty-seven".