129926221 has 2 divisors, whose sum is σ = 129926222. Its totient is φ = 129926220.

The previous prime is 129926197. The next prime is 129926227. The reversal of 129926221 is 122629921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78517321 + 51408900 = 8861^2 + 7170^2 .

It is a cyclic number.

It is not a de Polignac number, because 129926221 - 2⁹ = 129925709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129926227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64963110 + 64963111.

It is an arithmetic number, because the mean of its divisors is an integer number (64963111).

Almost surely, 2^129926221 is an apocalyptic number.

It is an amenable number.

129926221 is a deficient number, since it is larger than the sum of its proper divisors (1).

129926221 is an equidigital number, since it uses as much as digits as its factorization.

129926221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 129926221 is about 11398.5183686302. The cubic root of 129926221 is about 506.4838505856.

The spelling of 129926221 in words is "one hundred twenty-nine million, nine hundred twenty-six thousand, two hundred twenty-one".