180129221 has 2 divisors, whose sum is σ = 180129222. Its totient is φ = 180129220.

The previous prime is 180129211. The next prime is 180129241. The reversal of 180129221 is 122921081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178516321 + 1612900 = 13361^2 + 1270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-180129221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (180129211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90064610 + 90064611.

It is an arithmetic number, because the mean of its divisors is an integer number (90064611).

Almost surely, 2^180129221 is an apocalyptic number.

It is an amenable number.

180129221 is a deficient number, since it is larger than the sum of its proper divisors (1).

180129221 is an equidigital number, since it uses as much as digits as its factorization.

180129221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 180129221 is about 13421.2227833383. Note that the first 3 decimals coincide. The cubic root of 180129221 is about 564.7566979167.

The spelling of 180129221 in words is "one hundred eighty million, one hundred twenty-nine thousand, two hundred twenty-one".