8129106221 has 2 divisors, whose sum is σ = 8129106222. Its totient is φ = 8129106220.

The previous prime is 8129106217. The next prime is 8129106247. The reversal of 8129106221 is 1226019218.

8129106221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4908543721 + 3220562500 = 70061^2 + 56750^2 .

It is a cyclic number.

It is not a de Polignac number, because 8129106221 - 2² = 8129106217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8129105221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4064553110 + 4064553111.

It is an arithmetic number, because the mean of its divisors is an integer number (4064553111).

Almost surely, 2^8129106221 is an apocalyptic number.

It is an amenable number.

8129106221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8129106221 is an equidigital number, since it uses as much as digits as its factorization.

8129106221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 8129106221 is about 90161.5562254778. The cubic root of 8129106221 is about 2010.7014886904.

The spelling of 8129106221 in words is "eight billion, one hundred twenty-nine million, one hundred six thousand, two hundred twenty-one".