78857739738 has 24 divisors (see below), whose sum is σ = 170865227988. Its totient is φ = 26284868352.

The previous prime is 78857739721. The next prime is 78857739743. The reversal of 78857739738 is 83793775887.

It can be written as a sum of positive squares in 2 ways, for example, as 76904718489 + 1953021249 = 277317^2 + 44193^2 .

It is a super-2 number, since 2×78857739738² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 477120 + ... + 620772.

Almost surely, 2^78857739738 is an apocalyptic number.

78857739738 is an abundant number, since it is smaller than the sum of its proper divisors (92007488250).

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

78857739738 is a wasteful number, since it uses less digits than its factorization.

78857739738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174158 (or 174155 counting only the distinct ones).

The product of its digits is 497871360, while the sum is 72.

The spelling of 78857739738 in words is "seventy-eight billion, eight hundred fifty-seven million, seven hundred thirty-nine thousand, seven hundred thirty-eight".