8221520765 has 8 divisors (see below), whose sum is σ = 9902231808. Its totient is φ = 6552945360.

The previous prime is 8221520759. The next prime is 8221520767. The reversal of 8221520765 is 5670251228.

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

It is not a de Polignac number, because 8221520765 - 2¹² = 8221516669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8221520767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3032417 + ... + 3035126.

It is an arithmetic number, because the mean of its divisors is an integer number (1237778976).

Almost surely, 2^8221520765 is an apocalyptic number.

It is an amenable number.

8221520765 is a deficient number, since it is larger than the sum of its proper divisors (1680711043).

8221520765 is a wasteful number, since it uses less digits than its factorization.

8221520765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6067819.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 8221520765 is about 90672.6020636885. The cubic root of 8221520765 is about 2018.2922504775.

The spelling of 8221520765 in words is "eight billion, two hundred twenty-one million, five hundred twenty thousand, seven hundred sixty-five".