1261728 has 72 divisors (see below), whose sum is σ = 3875508. Its totient is φ = 387072.

The previous prime is 1261721. The next prime is 1261739. The reversal of 1261728 is 8271621.

It can be written as a sum of positive squares in 2 ways, for example, as 1140624 + 121104 = 1068^2 + 348^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261721) 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, 3576 + ... + 3912.

2^1261728 is an apocalyptic number.

1261728 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 1261728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1937754).

1261728 is an abundant number, since it is smaller than the sum of its proper divisors (2613780).

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

1261728 is a wasteful number, since it uses less digits than its factorization.

1261728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 355 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1261728 is about 1123.2666646883. The cubic root of 1261728 is about 108.0575824620.

The spelling of 1261728 in words is "one million, two hundred sixty-one thousand, seven hundred twenty-eight".