1243440520 has 128 divisors (see below), whose sum is σ = 3402777600. Its totient is φ = 399200256.

The previous prime is 1243440509. The next prime is 1243440553. The reversal of 1243440520 is 250443421.

It is a happy number.

It is a super-2 number, since 2×1243440520² = 3092288653555740800, which contains 22 as substring.

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, 1137094 + ... + 1138186.

It is an arithmetic number, because the mean of its divisors is an integer number (26584200).

Almost surely, 2^1243440520 is an apocalyptic number.

1243440520 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 1243440520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1701388800).

1243440520 is an abundant number, since it is smaller than the sum of its proper divisors (2159337080).

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

1243440520 is a wasteful number, since it uses less digits than its factorization.

1243440520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367 (or 1363 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 1243440520 is about 35262.4519850790. The cubic root of 1243440520 is about 1075.3297765962.

Adding to 1243440520 its reverse (250443421), we get a palindrome (1493883941).

The spelling of 1243440520 in words is "one billion, two hundred forty-three million, four hundred forty thousand, five hundred twenty".