82805921 has 8 divisors (see below), whose sum is σ = 90741504. Its totient is φ = 74938320.

The previous prime is 82805881. The next prime is 82805953. The reversal of 82805921 is 12950828.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82805921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (82885921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14426 + ... + 19331.

It is an arithmetic number, because the mean of its divisors is an integer number (11342688).

Almost surely, 2^82805921 is an apocalyptic number.

It is an amenable number.

82805921 is a deficient number, since it is larger than the sum of its proper divisors (7935583).

82805921 is a wasteful number, since it uses less digits than its factorization.

82805921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33991.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 82805921 is about 9099.7758763609. The cubic root of 82805921 is about 435.8668072940.

The spelling of 82805921 in words is "eighty-two million, eight hundred five thousand, nine hundred twenty-one".