21042320347 has 2 divisors, whose sum is σ = 21042320348. Its totient is φ = 21042320346.

The previous prime is 21042320329. The next prime is 21042320491. The reversal of 21042320347 is 74302324012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21042320347 - 2⁷ = 21042320219 is a prime.

It is not a weakly prime, because it can be changed into another prime (21042320147) 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, 10521160173 + 10521160174.

It is an arithmetic number, because the mean of its divisors is an integer number (10521160174).

Almost surely, 2^21042320347 is an apocalyptic number.

21042320347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21042320347 is an equidigital number, since it uses as much as digits as its factorization.

21042320347 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 28.

Adding to 21042320347 its reverse (74302324012), we get a palindrome (95344644359).

The spelling of 21042320347 in words is "twenty-one billion, forty-two million, three hundred twenty thousand, three hundred forty-seven".