82809999 has 32 divisors (see below), whose sum is σ = 129792000. Its totient is φ = 52036992.

The previous prime is 82809997. The next prime is 82810019. The reversal of 82809999 is 99990828.

It is a Cunningham number, because it is equal to 9100²-1.

It is not a de Polignac number, because 82809999 - 2¹ = 82809997 is a prime.

82809999 is a modest number, since divided by 9999 gives 8280 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82809997) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 172642 + ... + 173120.

It is an arithmetic number, because the mean of its divisors is an integer number (4056000).

Almost surely, 2^82809999 is an apocalyptic number.

82809999 is a deficient number, since it is larger than the sum of its proper divisors (46982001).

82809999 is a wasteful number, since it uses less digits than its factorization.

82809999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 54.

The square root of 82809999 is about 9099.9999450549. Note that the first 4 decimals coincide. The cubic root of 82809999 is about 435.8739623204.

The spelling of 82809999 in words is "eighty-two million, eight hundred nine thousand, nine hundred ninety-nine".