999791121 has 16 divisors (see below), whose sum is σ = 1525091328. Its totient is φ = 570709200.

The previous prime is 999791113. The next prime is 999791123. The reversal of 999791121 is 121197999.

It is not a de Polignac number, because 999791121 - 2³ = 999791113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999791123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4125 + ... + 44906.

It is an arithmetic number, because the mean of its divisors is an integer number (95318208).

Almost surely, 2^999791121 is an apocalyptic number.

It is an amenable number.

999791121 is a deficient number, since it is larger than the sum of its proper divisors (525300207).

999791121 is a wasteful number, since it uses less digits than its factorization.

999791121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50012.

The product of its digits is 91854, while the sum is 48.

The square root of 999791121 is about 31619.4737622244. The cubic root of 999791121 is about 999.9303688183.

The spelling of 999791121 in words is "nine hundred ninety-nine million, seven hundred ninety-one thousand, one hundred twenty-one".