82172609 has 2 divisors, whose sum is σ = 82172610. Its totient is φ = 82172608.

The previous prime is 82172581. The next prime is 82172621. The reversal of 82172609 is 90627128.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80156209 + 2016400 = 8953^2 + 1420^2 .

It is a cyclic number.

It is not a de Polignac number, because 82172609 - 2²⁰ = 81124033 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (82172639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41086304 + 41086305.

It is an arithmetic number, because the mean of its divisors is an integer number (41086305).

Almost surely, 2^82172609 is an apocalyptic number.

It is an amenable number.

82172609 is a deficient number, since it is larger than the sum of its proper divisors (1).

82172609 is an equidigital number, since it uses as much as digits as its factorization.

82172609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 82172609 is about 9064.9108655298. The cubic root of 82172609 is about 434.7527709528.

The spelling of 82172609 in words is "eighty-two million, one hundred seventy-two thousand, six hundred nine".