9981320580 has 960 divisors, whose sum is σ = 42152140800. Its totient is φ = 1955923200.

The previous prime is 9981320579. The next prime is 9981320633. The reversal of 9981320580 is 850231899.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 140581945 + ... + 140582015.

It is an arithmetic number, because the mean of its divisors is an integer number (43908480).

Almost surely, 2^9981320580 is an apocalyptic number.

9981320580 is a gapful number since it is divisible by the number (90) 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 9981320580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21076070400).

9981320580 is an abundant number, since it is smaller than the sum of its proper divisors (32170820220).

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

9981320580 is a wasteful number, since it uses less digits than its factorization.

9981320580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 9981320580 is about 99906.5592441257. The cubic root of 9981320580 is about 2153.0924008973.

The spelling of 9981320580 in words is "nine billion, nine hundred eighty-one million, three hundred twenty thousand, five hundred eighty".