1243566540 has 144 divisors (see below), whose sum is σ = 3933226080. Its totient is φ = 326160000.

The previous prime is 1243566539. The next prime is 1243566547. The reversal of 1243566540 is 456653421.

1243566540 is a `hidden beast` number, since 1 + 2 + 43 + 566 + 54 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1243566495 and 1243566504.

It is not an unprimeable number, because it can be changed into a prime (1243566547) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8235465 + ... + 8235615.

It is an arithmetic number, because the mean of its divisors is an integer number (27314070).

Almost surely, 2^1243566540 is an apocalyptic number.

1243566540 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 1243566540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1966613040).

1243566540 is an abundant number, since it is smaller than the sum of its proper divisors (2689659540).

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

1243566540 is a wasteful number, since it uses less digits than its factorization.

1243566540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 1243566540 is about 35264.2388263238. The cubic root of 1243566540 is about 1075.3661028160.

The spelling of 1243566540 in words is "one billion, two hundred forty-three million, five hundred sixty-six thousand, five hundred forty".