20724368766391 has 2 divisors, whose sum is σ = 20724368766392. Its totient is φ = 20724368766390.

The previous prime is 20724368766389. The next prime is 20724368766433. The reversal of 20724368766391 is 19366786342702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20724368766391 - 2¹ = 20724368766389 is a prime.

Together with 20724368766389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20724368766301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10362184383195 + 10362184383196.

It is an arithmetic number, because the mean of its divisors is an integer number (10362184383196).

Almost surely, 2^{20724368766391} is an apocalyptic number.

20724368766391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20724368766391 is an equidigital number, since it uses as much as digits as its factorization.

20724368766391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 109734912, while the sum is 64.

The spelling of 20724368766391 in words is "twenty trillion, seven hundred twenty-four billion, three hundred sixty-eight million, seven hundred sixty-six thousand, three hundred ninety-one".