138207728178 has 48 divisors (see below), whose sum is σ = 322978907160. Its totient is φ = 42460284672.

The previous prime is 138207728147. The next prime is 138207728179. The reversal of 138207728178 is 871827702831.

138207728178 is a `hidden beast` number, since 1 + 382 + 0 + 77 + 28 + 178 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 32161759569 + 106045968609 = 179337^2 + 325647^2 .

It is a super-2 number, since 2×138207728178² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138207728179) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 299443 + ... + 605046.

Almost surely, 2^138207728178 is an apocalyptic number.

138207728178 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

138207728178 is an abundant number, since it is smaller than the sum of its proper divisors (184771178982).

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

138207728178 is a wasteful number, since it uses less digits than its factorization.

138207728178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905163 (or 905160 counting only the distinct ones).

The product of its (nonzero) digits is 2107392, while the sum is 54.

The spelling of 138207728178 in words is "one hundred thirty-eight billion, two hundred seven million, seven hundred twenty-eight thousand, one hundred seventy-eight".