9991650 has 48 divisors (see below), whose sum is σ = 25221600. Its totient is φ = 2616960.

The previous prime is 9991649. The next prime is 9991669. The reversal of 9991650 is 561999.

9991650 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 9991599 and 9991608.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8286 + ... + 9414.

It is an arithmetic number, because the mean of its divisors is an integer number (525450).

Almost surely, 2^9991650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9991650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12610800).

9991650 is an abundant number, since it is smaller than the sum of its proper divisors (15229950).

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

9991650 is a wasteful number, since it uses less digits than its factorization.

9991650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203 (or 1198 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 9991650 is about 3160.9571335278. The cubic root of 9991650 is about 215.3834872063.

The spelling of 9991650 in words is "nine million, nine hundred ninety-one thousand, six hundred fifty".