81726103519 has 2 divisors, whose sum is σ = 81726103520. Its totient is φ = 81726103518.

The previous prime is 81726103517. The next prime is 81726103523. The reversal of 81726103519 is 91530162718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81726103519 - 2¹ = 81726103517 is a prime.

It is a super-4 number, since 4×81726103519⁴ (a number of 45 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 81726103517, 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 (81726103517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40863051759 + 40863051760.

It is an arithmetic number, because the mean of its divisors is an integer number (40863051760).

Almost surely, 2^81726103519 is an apocalyptic number.

81726103519 is a deficient number, since it is larger than the sum of its proper divisors (1).

81726103519 is an equidigital number, since it uses as much as digits as its factorization.

81726103519 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The spelling of 81726103519 in words is "eighty-one billion, seven hundred twenty-six million, one hundred three thousand, five hundred nineteen".