921099 has 4 divisors (see below), whose sum is σ = 1228136. Its totient is φ = 614064.

The previous prime is 921091. The next prime is 921121. The reversal of 921099 is 990129.

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

It is not a de Polignac number, because 921099 - 2³ = 921091 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921091) 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, 153514 + ... + 153519.

It is an arithmetic number, because the mean of its divisors is an integer number (307034).

2⁹²¹⁰⁹⁹ is an apocalyptic number.

921099 is a deficient number, since it is larger than the sum of its proper divisors (307037).

921099 is a wasteful number, since it uses less digits than its factorization.

921099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307036.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 921099 is about 959.7390270277. The cubic root of 921099 is about 97.2975945707.

Adding to 921099 its sum of digits (30), we get a palindrome (921129).

The spelling of 921099 in words is "nine hundred twenty-one thousand, ninety-nine".