9815220 has 72 divisors (see below), whose sum is σ = 30750720. Its totient is φ = 2531520.

The previous prime is 9815219. The next prime is 9815231. The reversal of 9815220 is 225189.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4701 + ... + 6459.

Almost surely, 2^9815220 is an apocalyptic number.

9815220 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9815220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15375360).

9815220 is an abundant number, since it is smaller than the sum of its proper divisors (20935500).

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

9815220 is a wasteful number, since it uses less digits than its factorization.

9815220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1805 (or 1800 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 9815220 is about 3132.9251507178. The cubic root of 9815220 is about 214.1082225489.

The spelling of 9815220 in words is "nine million, eight hundred fifteen thousand, two hundred twenty".