8221291872 has 24 divisors (see below), whose sum is σ = 21580891416. Its totient is φ = 2740430592.

The previous prime is 8221291823. The next prime is 8221291889. The reversal of 8221291872 is 2781921228.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×8221291872² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42819133 + ... + 42819324.

It is an arithmetic number, because the mean of its divisors is an integer number (899203809).

Almost surely, 2^8221291872 is an apocalyptic number.

It is an amenable number.

8221291872 is an abundant number, since it is smaller than the sum of its proper divisors (13359599544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8221291872 is a wasteful number, since it uses less digits than its factorization.

8221291872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85638470 (or 85638462 counting only the distinct ones).

The product of its digits is 64512, while the sum is 42.

The square root of 8221291872 is about 90671.3398599580. The cubic root of 8221291872 is about 2018.2735200719.

The spelling of 8221291872 in words is "eight billion, two hundred twenty-one million, two hundred ninety-one thousand, eight hundred seventy-two".