1228320 has 72 divisors (see below), whose sum is σ = 4196556. Its totient is φ = 327168.

The previous prime is 1228309. The next prime is 1228327. The reversal of 1228320 is 238221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1089936 + 138384 = 1044^2 + 372^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1228293 and 1228302.

It is not an unprimeable number, because it can be changed into a prime (1228327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1014 + ... + 1866.

2^1228320 is an apocalyptic number.

1228320 is a gapful number since it is divisible by the number (10) 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 1228320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2098278).

1228320 is an abundant number, since it is smaller than the sum of its proper divisors (2968236).

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

1228320 is a wasteful number, since it uses less digits than its factorization.

1228320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1228320 is about 1108.2959893458. The cubic root of 1228320 is about 107.0953236770.

Subtracting from 1228320 its reverse (238221), we obtain a palindrome (990099).

The spelling of 1228320 in words is "one million, two hundred twenty-eight thousand, three hundred twenty".