1243908138 has 32 divisors (see below), whose sum is σ = 2718182592. Its totient is φ = 376358400.

The previous prime is 1243908121. The next prime is 1243908161. The reversal of 1243908138 is 8318093421.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1243908096 and 1243908105.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29370 + ... + 57882.

It is an arithmetic number, because the mean of its divisors is an integer number (84943206).

Almost surely, 2^1243908138 is an apocalyptic number.

1243908138 is an abundant number, since it is smaller than the sum of its proper divisors (1474274454).

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

1243908138 is a wasteful number, since it uses less digits than its factorization.

1243908138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29190.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 1243908138 is about 35269.0818990231. The cubic root of 1243908138 is about 1075.4645586867.

The spelling of 1243908138 in words is "one billion, two hundred forty-three million, nine hundred eight thousand, one hundred thirty-eight".