891089109 has 12 divisors (see below), whose sum is σ = 1287538252. Its totient is φ = 593870400.

The previous prime is 891089099. The next prime is 891089123. The reversal of 891089109 is 901980198.

It can be written as a sum of positive squares in 2 ways, for example, as 287404209 + 603684900 = 16953^2 + 24570^2 .

It is not a de Polignac number, because 891089109 - 2⁵ = 891089077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891089149) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17889 + ... + 45849.

Almost surely, 2^891089109 is an apocalyptic number.

It is an amenable number.

891089109 is a deficient number, since it is larger than the sum of its proper divisors (396449143).

891089109 is a wasteful number, since it uses less digits than its factorization.

891089109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31508 (or 31505 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 45.

The square root of 891089109 is about 29851.1157077922. The cubic root of 891089109 is about 962.2923765126.

It can be divided in two parts, 891089 and 109, that added together give a palindrome (891198).

The spelling of 891089109 in words is "eight hundred ninety-one million, eighty-nine thousand, one hundred nine".