129284821 has 2 divisors, whose sum is σ = 129284822. Its totient is φ = 129284820.

The previous prime is 129284819. The next prime is 129284833. The reversal of 129284821 is 128482921.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129276900 + 7921 = 11370^2 + 89^2 .

It is a cyclic number.

It is not a de Polignac number, because 129284821 - 2¹ = 129284819 is a prime.

Together with 129284819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129284021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64642410 + 64642411.

It is an arithmetic number, because the mean of its divisors is an integer number (64642411).

Almost surely, 2^129284821 is an apocalyptic number.

It is an amenable number.

129284821 is a deficient number, since it is larger than the sum of its proper divisors (1).

129284821 is an equidigital number, since it uses as much as digits as its factorization.

129284821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 37.

The square root of 129284821 is about 11370.3483236003. The cubic root of 129284821 is about 505.6490312005.

The spelling of 129284821 in words is "one hundred twenty-nine million, two hundred eighty-four thousand, eight hundred twenty-one".