1128891 has 4 divisors (see below), whose sum is σ = 1505192. Its totient is φ = 752592.

The previous prime is 1128889. The next prime is 1128899. The reversal of 1128891 is 1988211.

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

It is not a de Polignac number, because 1128891 - 2¹ = 1128889 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (1128899) 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, 188146 + ... + 188151.

It is an arithmetic number, because the mean of its divisors is an integer number (376298).

2^1128891 is an apocalyptic number.

1128891 is a deficient number, since it is larger than the sum of its proper divisors (376301).

1128891 is an equidigital number, since it uses as much as digits as its factorization.

1128891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376300.

The product of its digits is 1152, while the sum is 30.

The square root of 1128891 is about 1062.4928235052. The cubic root of 1128891 is about 104.1239584565.

The spelling of 1128891 in words is "one million, one hundred twenty-eight thousand, eight hundred ninety-one".