9912780 has 120 divisors (see below), whose sum is σ = 32321520. Its totient is φ = 2540160.

The previous prime is 9912779. The next prime is 9912803. The reversal of 9912780 is 872199.

It is a happy number.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 46875 + ... + 47085.

It is an arithmetic number, because the mean of its divisors is an integer number (269346).

Almost surely, 2^9912780 is an apocalyptic number.

9912780 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 9912780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16160760).

9912780 is an abundant number, since it is smaller than the sum of its proper divisors (22408740).

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

9912780 is a wasteful number, since it uses less digits than its factorization.

9912780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 9912780 is about 3148.4567648294. The cubic root of 9912780 is about 214.8152730940.

The spelling of 9912780 in words is "nine million, nine hundred twelve thousand, seven hundred eighty".