1089891 has 24 divisors (see below), whose sum is σ = 1750320. Its totient is φ = 648000.

The previous prime is 1089877. The next prime is 1089917. The reversal of 1089891 is 1989801.

It is not a de Polignac number, because 1089891 - 2¹¹ = 1087843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1089841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9945 + ... + 10053.

It is an arithmetic number, because the mean of its divisors is an integer number (72930).

2^1089891 is an apocalyptic number.

1089891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1089891 is a deficient number, since it is larger than the sum of its proper divisors (660429).

1089891 is a wasteful number, since it uses less digits than its factorization.

1089891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 1089891 is about 1043.9784480534. The cubic root of 1089891 is about 102.9108160679.

It can be divided in two parts, 1089 and 891, that multiplied together give a cube (970299 = 99³).

The spelling of 1089891 in words is "one million, eighty-nine thousand, eight hundred ninety-one".