999133221 has 16 divisors (see below), whose sum is σ = 1408130240. Its totient is φ = 628404480.

The previous prime is 999133189. The next prime is 999133241. The reversal of 999133221 is 122331999.

It is not a de Polignac number, because 999133221 - 2⁵ = 999133189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 999133221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999133241) 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, 22630 + ... + 50103.

It is an arithmetic number, because the mean of its divisors is an integer number (88008140).

Almost surely, 2^999133221 is an apocalyptic number.

It is an amenable number.

999133221 is a deficient number, since it is larger than the sum of its proper divisors (408997019).

999133221 is a wasteful number, since it uses less digits than its factorization.

999133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72996.

The product of its digits is 26244, while the sum is 39.

The square root of 999133221 is about 31609.0686512589. The cubic root of 999133221 is about 999.7109901480.

The spelling of 999133221 in words is "nine hundred ninety-nine million, one hundred thirty-three thousand, two hundred twenty-one".