891109172 has 12 divisors (see below), whose sum is σ = 1560204996. Its totient is φ = 445336320.

The previous prime is 891109103. The next prime is 891109181. The reversal of 891109172 is 271901198.

It can be written as a sum of positive squares in 2 ways, for example, as 528816016 + 362293156 = 22996^2 + 19034^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45203 + ... + 61850.

It is an arithmetic number, because the mean of its divisors is an integer number (130017083).

Almost surely, 2^891109172 is an apocalyptic number.

It is an amenable number.

891109172 is a deficient number, since it is larger than the sum of its proper divisors (669095824).

891109172 is a wasteful number, since it uses less digits than its factorization.

891109172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109138 (or 109136 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 38.

The square root of 891109172 is about 29851.4517569917. The cubic root of 891109172 is about 962.2995985091.

The spelling of 891109172 in words is "eight hundred ninety-one million, one hundred nine thousand, one hundred seventy-two".