921138 has 8 divisors (see below), whose sum is σ = 1842288. Its totient is φ = 307044.

The previous prime is 921133. The next prime is 921143. The reversal of 921138 is 831129.

It is an interprime number because it is at equal distance from previous prime (921133) and next prime (921143).

It is a sphenic number, since it is the product of 3 distinct primes.

921138 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (921133) 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, 76756 + ... + 76767.

It is an arithmetic number, because the mean of its divisors is an integer number (230286).

2⁹²¹¹³⁸ is an apocalyptic number.

921138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

921138 is a wasteful number, since it uses less digits than its factorization.

921138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153528.

The product of its digits is 432, while the sum is 24.

The square root of 921138 is about 959.7593448360. The cubic root of 921138 is about 97.2989677683.

Subtracting from 921138 its reverse (831129), we obtain a palindrome (90009).

The spelling of 921138 in words is "nine hundred twenty-one thousand, one hundred thirty-eight".