1089891000 has 384 divisors, whose sum is σ = 4095748800. Its totient is φ = 259200000.

The previous prime is 1089890983. The next prime is 1089891001. The reversal of 1089891000 is 1989801.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1089891001) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9998946 + ... + 9999054.

Almost surely, 2^1089891000 is an apocalyptic number.

1089891000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1089891000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2047874400).

1089891000 is an abundant number, since it is smaller than the sum of its proper divisors (3005857800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1089891000 is a wasteful number, since it uses less digits than its factorization.

1089891000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 231 counting only the distinct ones).

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

The square root of 1089891000 is about 33013.4972397654. The cubic root of 1089891000 is about 1029.1081606791.

It can be divided in two parts, 1089 and 891000, that multiplied together give a cube (970299000 = 990³).

The spelling of 1089891000 in words is "one billion, eighty-nine million, eight hundred ninety-one thousand".