1243272520 has 128 divisors (see below), whose sum is σ = 3364623360. Its totient is φ = 404490240.

The previous prime is 1243272493. The next prime is 1243272523. The reversal of 1243272520 is 252723421.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (1243272523) by changing a digit.

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, 423297 + ... + 426223.

It is an arithmetic number, because the mean of its divisors is an integer number (26286120).

Almost surely, 2^1243272520 is an apocalyptic number.

1243272520 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 1243272520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1682311680).

1243272520 is an abundant number, since it is smaller than the sum of its proper divisors (2121350840).

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

1243272520 is a wasteful number, since it uses less digits than its factorization.

1243272520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3023 (or 3019 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 1243272520 is about 35260.0697673728. The cubic root of 1243272520 is about 1075.2813455062.

Adding to 1243272520 its reverse (252723421), we get a palindrome (1495995941).

The spelling of 1243272520 in words is "one billion, two hundred forty-three million, two hundred seventy-two thousand, five hundred twenty".