1243105540 has 12 divisors (see below), whose sum is σ = 2610521676. Its totient is φ = 497242208.

The previous prime is 1243105511. The next prime is 1243105547. The reversal of 1243105540 is 455013421.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 493550656 + 749554884 = 22216^2 + 27378^2 .

It is a super-2 number, since 2×1243105540² = 3090622767157383200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1243105547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31077619 + ... + 31077658.

It is an arithmetic number, because the mean of its divisors is an integer number (217543473).

Almost surely, 2^1243105540 is an apocalyptic number.

1243105540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243105540 is an abundant number, since it is smaller than the sum of its proper divisors (1367416136).

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

1243105540 is a wasteful number, since it uses less digits than its factorization.

1243105540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62155286 (or 62155284 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 1243105540 is about 35257.7018536376. The cubic root of 1243105540 is about 1075.2332041387.

Adding to 1243105540 its reverse (455013421), we get a palindrome (1698118961).

The spelling of 1243105540 in words is "one billion, two hundred forty-three million, one hundred five thousand, five hundred forty".