1243997728 has 24 divisors (see below), whose sum is σ = 2508857820. Its totient is φ = 606827520.

The previous prime is 1243997723. The next prime is 1243997747. The reversal of 1243997728 is 8277993421.

It can be written as a sum of positive squares in 2 ways, for example, as 1239884944 + 4112784 = 35212^2 + 2028^2 .

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1243997723) 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, 472773 + ... + 475396.

Almost surely, 2^1243997728 is an apocalyptic number.

It is an amenable number.

1243997728 is an abundant number, since it is smaller than the sum of its proper divisors (1264860092).

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

1243997728 is an equidigital number, since it uses as much as digits as its factorization.

1243997728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948220 (or 948212 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 52.

The square root of 1243997728 is about 35270.3519687570. The cubic root of 1243997728 is about 1075.4903774627.

The spelling of 1243997728 in words is "one billion, two hundred forty-three million, nine hundred ninety-seven thousand, seven hundred twenty-eight".