9921237888 has 64 divisors (see below), whose sum is σ = 26471692800. Its totient is φ = 3292220928.

The previous prime is 9921237883. The next prime is 9921237901. The reversal of 9921237888 is 8887321299.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×9921237888² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9921237881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27703 + ... + 143561.

It is an arithmetic number, because the mean of its divisors is an integer number (413620200).

Almost surely, 2^9921237888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9921237888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13235846400).

9921237888 is an abundant number, since it is smaller than the sum of its proper divisors (16550454912).

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

9921237888 is a wasteful number, since it uses less digits than its factorization.

9921237888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116099 (or 116087 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 57.

The square root of 9921237888 is about 99605.4109373582. The cubic root of 9921237888 is about 2148.7635138632.

The spelling of 9921237888 in words is "nine billion, nine hundred twenty-one million, two hundred thirty-seven thousand, eight hundred eighty-eight".