9213889922721 has 45 divisors (see below), whose sum is σ = 15129473193219. Its totient is φ = 5583993584400.

The previous prime is 9213889922707. The next prime is 9213889922737. The reversal of 9213889922721 is 1272299883129.

The square root of 9213889922721 is 3035439.

It is a perfect power (a square), and thus also a powerful number.

9213889922721 is a `hidden beast` number, since 9 + 2 + 1 + 388 + 9 + 9 + 227 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9170667512721 + 43222410000 = 3028311^2 + 207900^2 .

It is not a de Polignac number, because 9213889922721 - 2¹³ = 9213889914529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9213889922761) 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 44 ways as a sum of consecutive naturals, for example, 300493131 + ... + 300523791.

Almost surely, 2^{9213889922721} is an apocalyptic number.

9213889922721 is the 3035439-th square number.

9213889922721 is the 1517720-th centered octagonal number.

It is an amenable number.

9213889922721 is a deficient number, since it is larger than the sum of its proper divisors (5915583270498).

9213889922721 is an frugal number, since it uses more digits than its factorization.

9213889922721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61356 (or 30675 counting only the distinct ones).

The product of its digits is 15676416, while the sum is 63.

The spelling of 9213889922721 in words is "nine trillion, two hundred thirteen billion, eight hundred eighty-nine million, nine hundred twenty-two thousand, seven hundred twenty-one".