129606221 has 4 divisors (see below), whose sum is σ = 129787200. Its totient is φ = 129425244.

The previous prime is 129606209. The next prime is 129606233. The reversal of 129606221 is 122606921.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122606921 = 113 ⋅1085017.

It is an interprime number because it is at equal distance from previous prime (129606209) and next prime (129606233).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129606221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129606121) 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, 89411 + ... + 90848.

It is an arithmetic number, because the mean of its divisors is an integer number (32446800).

Almost surely, 2^129606221 is an apocalyptic number.

It is an amenable number.

129606221 is a deficient number, since it is larger than the sum of its proper divisors (180979).

129606221 is an equidigital number, since it uses as much as digits as its factorization.

129606221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180978.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 129606221 is about 11384.4728029013. The cubic root of 129606221 is about 506.0676962654.

The spelling of 129606221 in words is "one hundred twenty-nine million, six hundred six thousand, two hundred twenty-one".