172208137 has 2 divisors, whose sum is σ = 172208138. Its totient is φ = 172208136.

The previous prime is 172208089. The next prime is 172208149. The reversal of 172208137 is 731802271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168506361 + 3701776 = 12981^2 + 1924^2 .

It is a cyclic number.

It is not a de Polignac number, because 172208137 - 2⁷ = 172208009 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 172208099 and 172208108.

It is not a weakly prime, because it can be changed into another prime (172208537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86104068 + 86104069.

It is an arithmetic number, because the mean of its divisors is an integer number (86104069).

Almost surely, 2^172208137 is an apocalyptic number.

It is an amenable number.

172208137 is a deficient number, since it is larger than the sum of its proper divisors (1).

172208137 is an equidigital number, since it uses as much as digits as its factorization.

172208137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 172208137 is about 13122.8097982101. The cubic root of 172208137 is about 556.3540102269.

The spelling of 172208137 in words is "one hundred seventy-two million, two hundred eight thousand, one hundred thirty-seven".