9121855 has 4 divisors (see below), whose sum is σ = 10946232. Its totient is φ = 7297480.

The previous prime is 9121841. The next prime is 9121859. The reversal of 9121855 is 5581219.

9121855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 9121855 - 2⁷ = 9121727 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

9121855 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9121859) 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, 912181 + ... + 912190.

It is an arithmetic number, because the mean of its divisors is an integer number (2736558).

Almost surely, 2^9121855 is an apocalyptic number.

9121855 is a deficient number, since it is larger than the sum of its proper divisors (1824377).

9121855 is a wasteful number, since it uses less digits than its factorization.

9121855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1824376.

The product of its digits is 3600, while the sum is 31.

The square root of 9121855 is about 3020.2408844329. The cubic root of 9121855 is about 208.9429497147.

The spelling of 9121855 in words is "nine million, one hundred twenty-one thousand, eight hundred fifty-five".