138172169 has 6 divisors (see below), whose sum is σ = 138753114. Its totient is φ = 137592800.

The previous prime is 138172163. The next prime is 138172189. The reversal of 138172169 is 961271831.

It can be written as a sum of positive squares in only one way, i.e., 137827600 + 344569 = 11740^2 + 587^2 .

It is not a de Polignac number, because 138172169 - 2²⁰ = 137123593 is a prime.

It is a super-2 number, since 2×138172169² = 38183096572329122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138172163) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 235094 + ... + 235680.

It is an arithmetic number, because the mean of its divisors is an integer number (23125519).

Almost surely, 2^138172169 is an apocalyptic number.

It is an amenable number.

138172169 is a deficient number, since it is larger than the sum of its proper divisors (580945).

138172169 is an frugal number, since it uses more digits than its factorization.

138172169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575 (or 988 counting only the distinct ones).

The product of its digits is 18144, while the sum is 38.

The square root of 138172169 is about 11754.6658395720. The cubic root of 138172169 is about 516.9797414826.

The spelling of 138172169 in words is "one hundred thirty-eight million, one hundred seventy-two thousand, one hundred sixty-nine".