9921911616 has 126 divisors (see below), whose sum is σ = 29532939410. Its totient is φ = 3307163904.

The previous prime is 9921911609. The next prime is 9921911621. The reversal of 9921911616 is 6161191299.

9921911616 is a `hidden beast` number, since 9 + 9 + 2 + 19 + 11 + 616 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5553230400 + 4368681216 = 74520^2 + 66096^2 .

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 408090 + ... + 431718.

Almost surely, 2^9921911616 is an apocalyptic number.

9921911616 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9921911616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14766469705).

9921911616 is an abundant number, since it is smaller than the sum of its proper divisors (19611027794).

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

9921911616 is an frugal number, since it uses more digits than its factorization.

9921911616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23665 (or 23634 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The square root of 9921911616 is about 99608.7928648872. The cubic root of 9921911616 is about 2148.8121519261.

The spelling of 9921911616 in words is "nine billion, nine hundred twenty-one million, nine hundred eleven thousand, six hundred sixteen".