129971225 has 6 divisors (see below), whose sum is σ = 161164350. Its totient is φ = 103976960.

The previous prime is 129971221. The next prime is 129971249. The reversal of 129971225 is 522179921.

It can be written as a sum of positive squares in 3 ways, for example, as 375769 + 129595456 = 613^2 + 11384^2 .

It is not a de Polignac number, because 129971225 - 2² = 129971221 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129971221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2599400 + ... + 2599449.

It is an arithmetic number, because the mean of its divisors is an integer number (26860725).

Almost surely, 2^129971225 is an apocalyptic number.

It is an amenable number.

129971225 is a deficient number, since it is larger than the sum of its proper divisors (31193125).

129971225 is an equidigital number, since it uses as much as digits as its factorization.

129971225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5198859 (or 5198854 counting only the distinct ones).

The product of its digits is 22680, while the sum is 38.

The square root of 129971225 is about 11400.4923139310. The cubic root of 129971225 is about 506.5423226625.

The spelling of 129971225 in words is "one hundred twenty-nine million, nine hundred seventy-one thousand, two hundred twenty-five".