21328970849 has 2 divisors, whose sum is σ = 21328970850. Its totient is φ = 21328970848.

The previous prime is 21328970843. The next prime is 21328970869. The reversal of 21328970849 is 94807982312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20211740224 + 1117230625 = 142168^2 + 33425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21328970849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21328970849.

It is not a weakly prime, because it can be changed into another prime (21328970843) 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, 10664485424 + 10664485425.

It is an arithmetic number, because the mean of its divisors is an integer number (10664485425).

Almost surely, 2^21328970849 is an apocalyptic number.

It is an amenable number.

21328970849 is a deficient number, since it is larger than the sum of its proper divisors (1).

21328970849 is an equidigital number, since it uses as much as digits as its factorization.

21328970849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1741824, while the sum is 53.

The spelling of 21328970849 in words is "twenty-one billion, three hundred twenty-eight million, nine hundred seventy thousand, eight hundred forty-nine".