1243213440 has 256 divisors, whose sum is σ = 4559742720. Its totient is φ = 282230784.

The previous prime is 1243213423. The next prime is 1243213507. The reversal of 1243213440 is 443123421.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1243213440.

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 31 ways as a sum of consecutive naturals, for example, 3131322 + ... + 3131718.

It is an arithmetic number, because the mean of its divisors is an integer number (17811495).

Almost surely, 2^1243213440 is an apocalyptic number.

1243213440 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 1243213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2279871360).

1243213440 is an abundant number, since it is smaller than the sum of its proper divisors (3316529280).

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

1243213440 is a wasteful number, since it uses less digits than its factorization.

1243213440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 659 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 1243213440 is about 35259.2319825603. The cubic root of 1243213440 is about 1075.2643128693.

Adding to 1243213440 its reverse (443123421), we get a palindrome (1686336861).

The spelling of 1243213440 in words is "one billion, two hundred forty-three million, two hundred thirteen thousand, four hundred forty".