21713396447 has 2 divisors, whose sum is σ = 21713396448. Its totient is φ = 21713396446.

The previous prime is 21713396437. The next prime is 21713396449. The reversal of 21713396447 is 74469331712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21713396447 - 2¹⁶ = 21713330911 is a prime.

It is a super-3 number, since 3×21713396447³ (a number of 32 digits) contains 333 as substring.

Together with 21713396449, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21713396449) 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, 10856698223 + 10856698224.

It is an arithmetic number, because the mean of its divisors is an integer number (10856698224).

Almost surely, 2^21713396447 is an apocalyptic number.

21713396447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21713396447 is an equidigital number, since it uses as much as digits as its factorization.

21713396447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 47.

The spelling of 21713396447 in words is "twenty-one billion, seven hundred thirteen million, three hundred ninety-six thousand, four hundred forty-seven".