172686109 has 2 divisors, whose sum is σ = 172686110. Its totient is φ = 172686108.

The previous prime is 172686053. The next prime is 172686113. The reversal of 172686109 is 901686271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91145209 + 81540900 = 9547^2 + 9030^2 .

It is an emirp because it is prime and its reverse (901686271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172686109 - 2¹³ = 172677917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172686209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86343054 + 86343055.

It is an arithmetic number, because the mean of its divisors is an integer number (86343055).

Almost surely, 2^172686109 is an apocalyptic number.

It is an amenable number.

172686109 is a deficient number, since it is larger than the sum of its proper divisors (1).

172686109 is an equidigital number, since it uses as much as digits as its factorization.

172686109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 172686109 is about 13141.0086751360. The cubic root of 172686109 is about 556.8682638817.

The spelling of 172686109 in words is "one hundred seventy-two million, six hundred eighty-six thousand, one hundred nine".