82172309 has 8 divisors (see below), whose sum is σ = 85345920. Its totient is φ = 79058176.

The previous prime is 82172297. The next prime is 82172317. The reversal of 82172309 is 90327128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 82172309 - 2⁸ = 82172053 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82172329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12044 + ... + 17589.

It is an arithmetic number, because the mean of its divisors is an integer number (10668240).

Almost surely, 2^82172309 is an apocalyptic number.

It is an amenable number.

82172309 is a deficient number, since it is larger than the sum of its proper divisors (3173611).

82172309 is a wasteful number, since it uses less digits than its factorization.

82172309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29739.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 82172309 is about 9064.8943181926. The cubic root of 82172309 is about 434.7522418796.

The spelling of 82172309 in words is "eighty-two million, one hundred seventy-two thousand, three hundred nine".