139040240161 has 3 divisors (see below), whose sum is σ = 139040613043. Its totient is φ = 139039867280.

The previous prime is 139040240123. The next prime is 139040240167. The reversal of 139040240161 is 161042040931.

The square root of 139040240161 is 372881.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 161042040931 = 1699 ⋅94786369.

It can be written as a sum of positive squares in only one way, i.e., 89951406561 + 49088833600 = 299919^2 + 221560^2 .

It is not a de Polignac number, because 139040240161 - 2⁹ = 139040239649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139040240167) by changing a digit.

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 2 ways as a sum of consecutive naturals, for example, 186441 + ... + 559321.

Almost surely, 2^139040240161 is an apocalyptic number.

139040240161 is the 372881-st square number.

139040240161 is the 186441-st centered octagonal number.

It is an amenable number.

139040240161 is a deficient number, since it is larger than the sum of its proper divisors (372882).

139040240161 is an frugal number, since it uses more digits than its factorization.

139040240161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745762 (or 372881 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

Multiplying 139040240161 by its product of nonzero digits (5184), we get a square (720784604994624 = 26847432²).

The spelling of 139040240161 in words is "one hundred thirty-nine billion, forty million, two hundred forty thousand, one hundred sixty-one".