129642281 has 2 divisors, whose sum is σ = 129642282. Its totient is φ = 129642280.

The previous prime is 129642277. The next prime is 129642299. The reversal of 129642281 is 182246921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80712256 + 48930025 = 8984^2 + 6995^2 .

It is a cyclic number.

It is not a de Polignac number, because 129642281 - 2² = 129642277 is a prime.

It is a super-2 number, since 2×129642281² = 33614242045765922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129642211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64821140 + 64821141.

It is an arithmetic number, because the mean of its divisors is an integer number (64821141).

Almost surely, 2^129642281 is an apocalyptic number.

It is an amenable number.

129642281 is a deficient number, since it is larger than the sum of its proper divisors (1).

129642281 is an equidigital number, since it uses as much as digits as its factorization.

129642281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 35.

The square root of 129642281 is about 11386.0564288080. The cubic root of 129642281 is about 506.1146258773.

The spelling of 129642281 in words is "one hundred twenty-nine million, six hundred forty-two thousand, two hundred eighty-one".