1220728 has 16 divisors (see below), whose sum is σ = 2300760. Its totient is φ = 607200.

The previous prime is 1220717. The next prime is 1220729. The reversal of 1220728 is 8270221.

It is a junction number, because it is equal to n+sod(n) for n = 1220699 and 1220708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2418 + ... + 2878.

2^1220728 is an apocalyptic number.

It is an amenable number.

1220728 is a deficient number, since it is larger than the sum of its proper divisors (1080032).

1220728 is a wasteful number, since it uses less digits than its factorization.

1220728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798 (or 794 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 1220728 is about 1104.8656026866. The cubic root of 1220728 is about 106.8742226042.

Adding to 1220728 its reverse (8270221), we get a palindrome (9490949).

The spelling of 1220728 in words is "one million, two hundred twenty thousand, seven hundred twenty-eight".