9951780 has 48 divisors (see below), whose sum is σ = 28465920. Its totient is φ = 2596608.

The previous prime is 9951769. The next prime is 9951793. The reversal of 9951780 is 871599.

It is a happy number.

9951780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1056 + ... + 4584.

It is an arithmetic number, because the mean of its divisors is an integer number (593040).

Almost surely, 2^9951780 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 9951780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14232960).

9951780 is an abundant number, since it is smaller than the sum of its proper divisors (18514140).

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

9951780 is a wasteful number, since it uses less digits than its factorization.

9951780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3588 (or 3586 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 9951780 is about 3154.6441954680. The cubic root of 9951780 is about 215.0966214355.

It can be divided in two parts, 9951 and 780, that added together give a triangular number (10731 = T₁₄₆).

The spelling of 9951780 in words is "nine million, nine hundred fifty-one thousand, seven hundred eighty".