129572221 has 2 divisors, whose sum is σ = 129572222. Its totient is φ = 129572220.

The previous prime is 129572207. The next prime is 129572237. The reversal of 129572221 is 122275921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115025625 + 14546596 = 10725^2 + 3814^2 .

It is an emirp because it is prime and its reverse (122275921) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129572221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129572291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64786110 + 64786111.

It is an arithmetic number, because the mean of its divisors is an integer number (64786111).

Almost surely, 2^129572221 is an apocalyptic number.

It is an amenable number.

129572221 is a deficient number, since it is larger than the sum of its proper divisors (1).

129572221 is an equidigital number, since it uses as much as digits as its factorization.

129572221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 129572221 is about 11382.9794430105. The cubic root of 129572221 is about 506.0234396282.

The spelling of 129572221 in words is "one hundred twenty-nine million, five hundred seventy-two thousand, two hundred twenty-one".