9861820 has 24 divisors (see below), whose sum is σ = 20823264. Its totient is φ = 3923136.

The previous prime is 9861781. The next prime is 9861821. The reversal of 9861820 is 281689.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9861821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2689 + ... + 5191.

It is an arithmetic number, because the mean of its divisors is an integer number (867636).

Almost surely, 2^9861820 is an apocalyptic number.

It is an amenable number.

9861820 is an abundant number, since it is smaller than the sum of its proper divisors (10961444).

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

9861820 is a wasteful number, since it uses less digits than its factorization.

9861820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709 (or 2707 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 9861820 is about 3140.3534832881. The cubic root of 9861820 is about 214.4465302868.

The spelling of 9861820 in words is "nine million, eight hundred sixty-one thousand, eight hundred twenty".