9969779028 has 144 divisors (see below), whose sum is σ = 27013896000. Its totient is φ = 2851706880.

The previous prime is 9969779023. The next prime is 9969779089. The reversal of 9969779028 is 8209779699.

9969779028 is a nontrivial binomial coefficient, being equal to C(141208, 2).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a self number, because there is not a number n which added to its sum of digits gives 9969779028.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9969779023) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10731268 + ... + 10732196.

It is an arithmetic number, because the mean of its divisors is an integer number (187596500).

Almost surely, 2^9969779028 is an apocalyptic number.

9969779028 is the 141207-th triangular number and also the 70604-th hexagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9969779028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13506948000).

9969779028 is an abundant number, since it is smaller than the sum of its proper divisors (17044116972).

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

9969779028 is a wasteful number, since it uses less digits than its factorization.

9969779028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1366 (or 1353 counting only the distinct ones).

The product of its (nonzero) digits is 30862944, while the sum is 66.

The square root of 9969779028 is about 99848.7808037735. The cubic root of 9969779028 is about 2152.2621963828.

The spelling of 9969779028 in words is "nine billion, nine hundred sixty-nine million, seven hundred seventy-nine thousand, twenty-eight".