1243801728 has 288 divisors, whose sum is σ = 4055027340. Its totient is φ = 363737088.

The previous prime is 1243801673. The next prime is 1243801733. The reversal of 1243801728 is 8271083421.

It can be written as a sum of positive squares in 2 ways, for example, as 1133803584 + 109998144 = 33672^2 + 10488^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1243801692 and 1243801701.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7922226 + ... + 7922382.

Almost surely, 2^1243801728 is an apocalyptic number.

1243801728 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 1243801728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2027513670).

1243801728 is an abundant number, since it is smaller than the sum of its proper divisors (2811225612).

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

1243801728 is a wasteful number, since it uses less digits than its factorization.

1243801728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 1243801728 is about 35267.5733216789. The cubic root of 1243801728 is about 1075.4338909754.

The spelling of 1243801728 in words is "one billion, two hundred forty-three million, eight hundred one thousand, seven hundred twenty-eight".