8205649921 has 8 divisors (see below), whose sum is σ = 9412492544. Its totient is φ = 7007459040.

The previous prime is 8205649889. The next prime is 8205649931. The reversal of 8205649921 is 1299465028.

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 8205649921 - 2⁵ = 8205649889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8205649931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2160900 + ... + 2164693.

It is an arithmetic number, because the mean of its divisors is an integer number (1176561568).

Almost surely, 2^8205649921 is an apocalyptic number.

It is an amenable number.

8205649921 is a deficient number, since it is larger than the sum of its proper divisors (1206842623).

8205649921 is a wasteful number, since it uses less digits than its factorization.

8205649921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4325871.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 8205649921 is about 90585.0424794292. The cubic root of 8205649921 is about 2016.9927084562.

The spelling of 8205649921 in words is "eight billion, two hundred five million, six hundred forty-nine thousand, nine hundred twenty-one".