1243440000 has 480 divisors, whose sum is σ = 4908772440. Its totient is φ = 299520000.

The previous prime is 1243439983. The next prime is 1243440017. The reversal of 1243440000 is 443421.

It is an interprime number because it is at equal distance from previous prime (1243439983) and next prime (1243440017).

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×1243440000² = 3092286067200000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 7919922 + ... + 7920078.

Almost surely, 2^1243440000 is an apocalyptic number.

1243440000 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 1243440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2454386220).

1243440000 is an abundant number, since it is smaller than the sum of its proper divisors (3665332440).

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

1243440000 is a wasteful number, since it uses less digits than its factorization.

1243440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 1243440000 is about 35262.4446117963. Note that the first 3 decimals coincide. The cubic root of 1243440000 is about 1075.3296266972.

Adding to 1243440000 its reverse (443421), we get a palindrome (1243883421).

The spelling of 1243440000 in words is "one billion, two hundred forty-three million, four hundred forty thousand".