129225221 has 2 divisors, whose sum is σ = 129225222. Its totient is φ = 129225220.

The previous prime is 129225197. The next prime is 129225223. The reversal of 129225221 is 122522921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124768900 + 4456321 = 11170^2 + 2111^2 .

It is a cyclic number.

It is not a de Polignac number, because 129225221 - 2¹⁸ = 128963077 is a prime.

Together with 129225223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129225223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64612610 + 64612611.

It is an arithmetic number, because the mean of its divisors is an integer number (64612611).

Almost surely, 2^129225221 is an apocalyptic number.

It is an amenable number.

129225221 is a deficient number, since it is larger than the sum of its proper divisors (1).

129225221 is an equidigital number, since it uses as much as digits as its factorization.

129225221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 129225221 is about 11367.7271694917. The cubic root of 129225221 is about 505.5713182507.

The spelling of 129225221 in words is "one hundred twenty-nine million, two hundred twenty-five thousand, two hundred twenty-one".