172561139 has 4 divisors (see below), whose sum is σ = 173704080. Its totient is φ = 171418200.

The previous prime is 172561117. The next prime is 172561141. The reversal of 172561139 is 931165271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931165271 = 239 ⋅3896089.

It is a cyclic number.

It is not a de Polignac number, because 172561139 - 2²⁴ = 155783923 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 172561099 and 172561108.

It is not an unprimeable number, because it can be changed into a prime (172560139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 571244 + ... + 571545.

It is an arithmetic number, because the mean of its divisors is an integer number (43426020).

Almost surely, 2^172561139 is an apocalyptic number.

172561139 is a deficient number, since it is larger than the sum of its proper divisors (1142941).

172561139 is a wasteful number, since it uses less digits than its factorization.

172561139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1142940.

The product of its digits is 11340, while the sum is 35.

The square root of 172561139 is about 13136.2528523168. The cubic root of 172561139 is about 556.7338994336.

The spelling of 172561139 in words is "one hundred seventy-two million, five hundred sixty-one thousand, one hundred thirty-nine".