21328970869 has 2 divisors, whose sum is σ = 21328970870. Its totient is φ = 21328970868.

The previous prime is 21328970849. The next prime is 21328970881. The reversal of 21328970869 is 96807982312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15862143025 + 5466827844 = 125945^2 + 73938^2 .

It is a cyclic number.

It is not a de Polignac number, because 21328970869 - 2¹⁵ = 21328938101 is a prime.

It is a super-2 number, since 2×21328970869² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21328970849) 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, 10664485434 + 10664485435.

It is an arithmetic number, because the mean of its divisors is an integer number (10664485435).

Almost surely, 2^21328970869 is an apocalyptic number.

It is an amenable number.

21328970869 is a deficient number, since it is larger than the sum of its proper divisors (1).

21328970869 is an equidigital number, since it uses as much as digits as its factorization.

21328970869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The spelling of 21328970869 in words is "twenty-one billion, three hundred twenty-eight million, nine hundred seventy thousand, eight hundred sixty-nine".