21713727719 has 2 divisors, whose sum is σ = 21713727720. Its totient is φ = 21713727718.

The previous prime is 21713727661. The next prime is 21713727733. The reversal of 21713727719 is 91772731712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21713727719 is a prime.

It is a super-2 number, since 2×21713727719² (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 (21713727769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10856863859 + 10856863860.

It is an arithmetic number, because the mean of its divisors is an integer number (10856863860).

Almost surely, 2^21713727719 is an apocalyptic number.

21713727719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21713727719 is an equidigital number, since it uses as much as digits as its factorization.

21713727719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259308, while the sum is 47.

The spelling of 21713727719 in words is "twenty-one billion, seven hundred thirteen million, seven hundred twenty-seven thousand, seven hundred nineteen".