1243456340 has 72 divisors (see below), whose sum is σ = 3042984672. Its totient is φ = 425570880.

The previous prime is 1243456297. The next prime is 1243456367. The reversal of 1243456340 is 436543421.

It is a junction number, because it is equal to n+sod(n) for n = 1243456297 and 1243456306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1068599 + ... + 1069761.

It is an arithmetic number, because the mean of its divisors is an integer number (42263676).

Almost surely, 2^1243456340 is an apocalyptic number.

1243456340 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 1243456340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1521492336).

1243456340 is an abundant number, since it is smaller than the sum of its proper divisors (1799528332).

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

1243456340 is a wasteful number, since it uses less digits than its factorization.

1243456340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277 (or 2268 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 1243456340 is about 35262.6763022888. The cubic root of 1243456340 is about 1075.3343369658.

Adding to 1243456340 its reverse (436543421), we get a palindrome (1679999761).

The spelling of 1243456340 in words is "one billion, two hundred forty-three million, four hundred fifty-six thousand, three hundred forty".