1243868138 has 24 divisors (see below), whose sum is σ = 2028145152. Its totient is φ = 571725504.

The previous prime is 1243868123. The next prime is 1243868147. The reversal of 1243868138 is 8318683421.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170 + ... + 49877.

It is an arithmetic number, because the mean of its divisors is an integer number (84506048).

Almost surely, 2^1243868138 is an apocalyptic number.

1243868138 is a deficient number, since it is larger than the sum of its proper divisors (784277014).

1243868138 is a wasteful number, since it uses less digits than its factorization.

1243868138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50126 (or 50109 counting only the distinct ones).

The product of its digits is 221184, while the sum is 44.

The square root of 1243868138 is about 35268.5148255494. The cubic root of 1243868138 is about 1075.4530307606.

The spelling of 1243868138 in words is "one billion, two hundred forty-three million, eight hundred sixty-eight thousand, one hundred thirty-eight".