138295478161 has 9 divisors (see below), whose sum is σ = 138806461521. Its totient is φ = 137786373072.

The previous prime is 138295478117. The next prime is 138295478177. The reversal of 138295478161 is 161874592831.

The square root of 138295478161 is 371881.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 25802318161 + 112493160000 = 160631^2 + 335400^2 .

It is not a de Polignac number, because 138295478161 - 2¹³ = 138295469969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138295488161) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 138711115 + ... + 138712111.

It is an arithmetic number, because the mean of its divisors is an integer number (15422940169).

Almost surely, 2^138295478161 is an apocalyptic number.

138295478161 is the 371881-st square number.

138295478161 is the 185941-st centered octagonal number.

It is an amenable number.

138295478161 is a deficient number, since it is larger than the sum of its proper divisors (510983360).

138295478161 is an frugal number, since it uses more digits than its factorization.

138295478161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2740 (or 1370 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 55.

The spelling of 138295478161 in words is "one hundred thirty-eight billion, two hundred ninety-five million, four hundred seventy-eight thousand, one hundred sixty-one".