129847021 has 2 divisors, whose sum is σ = 129847022. Its totient is φ = 129847020.

The previous prime is 129846991. The next prime is 129847051. The reversal of 129847021 is 120748921.

It is a balanced prime because it is at equal distance from previous prime (129846991) and next prime (129847051).

It can be written as a sum of positive squares in only one way, i.e., 129732100 + 114921 = 11390^2 + 339^2 .

It is a cyclic number.

It is not a de Polignac number, because 129847021 - 2¹⁵ = 129814253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129847051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64923510 + 64923511.

It is an arithmetic number, because the mean of its divisors is an integer number (64923511).

Almost surely, 2^129847021 is an apocalyptic number.

It is an amenable number.

129847021 is a deficient number, since it is larger than the sum of its proper divisors (1).

129847021 is an equidigital number, since it uses as much as digits as its factorization.

129847021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 129847021 is about 11395.0437032949. The cubic root of 129847021 is about 506.3809160787.

The spelling of 129847021 in words is "one hundred twenty-nine million, eight hundred forty-seven thousand, twenty-one".