1243540000 has 120 divisors (see below), whose sum is σ = 3095655948. Its totient is φ = 491520000.

The previous prime is 1243539971. The next prime is 1243540037. The reversal of 1243540000 is 453421.

It can be written as a sum of positive squares in 10 ways, for example, as 7033104 + 1236506896 = 2652^2 + 35164^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1243540000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1939680 + ... + 1940320.

Almost surely, 2^1243540000 is an apocalyptic number.

1243540000 is a gapful number since it is divisible by the number (10) 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 1243540000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1547827974).

1243540000 is an abundant number, since it is smaller than the sum of its proper divisors (1852115948).

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

1243540000 is an frugal number, since it uses more digits than its factorization.

1243540000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768 (or 745 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 1243540000 is about 35263.8625224180. The cubic root of 1243540000 is about 1075.3584526639.

Adding to 1243540000 its reverse (453421), we get a palindrome (1243993421).

The spelling of 1243540000 in words is "one billion, two hundred forty-three million, five hundred forty thousand".