8120231221 has 4 divisors (see below), whose sum is σ = 8128594944. Its totient is φ = 8111867500.

The previous prime is 8120231149. The next prime is 8120231243. The reversal of 8120231221 is 1221320218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8120231221 - 2¹⁵ = 8120198453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8120231192 and 8120231201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8120211221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4180405 + ... + 4182346.

It is an arithmetic number, because the mean of its divisors is an integer number (2032148736).

Almost surely, 2^8120231221 is an apocalyptic number.

It is an amenable number.

8120231221 is a deficient number, since it is larger than the sum of its proper divisors (8363723).

8120231221 is an equidigital number, since it uses as much as digits as its factorization.

8120231221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8363722.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 8120231221 is about 90112.3255775812. The cubic root of 8120231221 is about 2009.9694904736.

Adding to 8120231221 its reverse (1221320218), we get a palindrome (9341551439).

The spelling of 8120231221 in words is "eight billion, one hundred twenty million, two hundred thirty-one thousand, two hundred twenty-one".