1225728 has 132 divisors (see below), whose sum is σ = 4257760. Its totient is φ = 331776.

The previous prime is 1225727. The next prime is 1225729. The reversal of 1225728 is 8275221.

It is an interprime number because it is at equal distance from previous prime (1225727) and next prime (1225729).

It is a zygodrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225723) 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, 64503 + ... + 64521.

2^1225728 is an apocalyptic number.

1225728 is a gapful number since it is divisible by the number (18) 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 1225728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2128880).

1225728 is an abundant number, since it is smaller than the sum of its proper divisors (3032032).

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

1225728 is a wasteful number, since it uses less digits than its factorization.

1225728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52 (or 31 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 1225728 is about 1107.1260090884. The cubic root of 1225728 is about 107.0199398016.

It can be divided in two parts, 1225 and 728, that added together give a triangular number (1953 = T₆₂).

The spelling of 1225728 in words is "one million, two hundred twenty-five thousand, seven hundred twenty-eight".