21129432329 has 2 divisors, whose sum is σ = 21129432330. Its totient is φ = 21129432328.

The previous prime is 21129432319. The next prime is 21129432371. The reversal of 21129432329 is 92323492112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19895666704 + 1233765625 = 141052^2 + 35125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21129432329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21129432292 and 21129432301.

It is not a weakly prime, because it can be changed into another prime (21129432319) 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, 10564716164 + 10564716165.

It is an arithmetic number, because the mean of its divisors is an integer number (10564716165).

Almost surely, 2^21129432329 is an apocalyptic number.

It is an amenable number.

21129432329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21129432329 is an equidigital number, since it uses as much as digits as its factorization.

21129432329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 38.

The spelling of 21129432329 in words is "twenty-one billion, one hundred twenty-nine million, four hundred thirty-two thousand, three hundred twenty-nine".