9921221924 has 12 divisors (see below), whose sum is σ = 17362873500. Its totient is φ = 4960400928.

The previous prime is 9921221923. The next prime is 9921222037. The reversal of 9921221924 is 4291221299.

9921221924 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 6530256100 + 3390965824 = 80810^2 + 58232^2 .

It is not an unprimeable number, because it can be changed into a prime (9921221923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108902 + ... + 178050.

It is an arithmetic number, because the mean of its divisors is an integer number (1446906125).

Almost surely, 2^9921221924 is an apocalyptic number.

It is an amenable number.

9921221924 is a deficient number, since it is larger than the sum of its proper divisors (7441651576).

9921221924 is a wasteful number, since it uses less digits than its factorization.

9921221924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105022 (or 105020 counting only the distinct ones).

The product of its digits is 46656, while the sum is 41.

The square root of 9921221924 is about 99605.3308011173. The cubic root of 9921221924 is about 2148.7623613566.

The spelling of 9921221924 in words is "nine billion, nine hundred twenty-one million, two hundred twenty-one thousand, nine hundred twenty-four".