9999221784 has 16 divisors (see below), whose sum is σ = 24998054520. Its totient is φ = 3333073920.

The previous prime is 9999221783. The next prime is 9999221831. The reversal of 9999221784 is 4871229999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999221783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208317097 + ... + 208317144.

Almost surely, 2^9999221784 is an apocalyptic number.

It is an amenable number.

9999221784 is an abundant number, since it is smaller than the sum of its proper divisors (14998832736).

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

9999221784 is a wasteful number, since it uses less digits than its factorization.

9999221784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416634250 (or 416634246 counting only the distinct ones).

The product of its digits is 5878656, while the sum is 60.

The square root of 9999221784 is about 99996.1088442945. The cubic root of 9999221784 is about 2154.3788013972.

The spelling of 9999221784 in words is "nine billion, nine hundred ninety-nine million, two hundred twenty-one thousand, seven hundred eighty-four".