21304442389 has 2 divisors, whose sum is σ = 21304442390. Its totient is φ = 21304442388.

The previous prime is 21304442377. The next prime is 21304442429. The reversal of 21304442389 is 98324440312.

It is an a-pointer prime, because the next prime (21304442429) can be obtained adding 21304442389 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11531538225 + 9772904164 = 107385^2 + 98858^2 .

It is a cyclic number.

It is not a de Polignac number, because 21304442389 - 2²³ = 21296053781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21304442359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652221194 + 10652221195.

It is an arithmetic number, because the mean of its divisors is an integer number (10652221195).

Almost surely, 2^21304442389 is an apocalyptic number.

It is an amenable number.

21304442389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21304442389 is an equidigital number, since it uses as much as digits as its factorization.

21304442389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 40.

The spelling of 21304442389 in words is "twenty-one billion, three hundred four million, four hundred forty-two thousand, three hundred eighty-nine".