8991780 has 96 divisors (see below), whose sum is σ = 29245440. Its totient is φ = 2021760.

The previous prime is 8991779. The next prime is 8991799. The reversal of 8991780 is 871998.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33045 + ... + 33315.

It is an arithmetic number, because the mean of its divisors is an integer number (304640).

Almost surely, 2^8991780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8991780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14622720).

8991780 is an abundant number, since it is smaller than the sum of its proper divisors (20253660).

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

8991780 is a wasteful number, since it uses less digits than its factorization.

8991780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 8991780 is about 2998.6296870404. The cubic root of 8991780 is about 207.9450360195.

The spelling of 8991780 in words is "eight million, nine hundred ninety-one thousand, seven hundred eighty".