81390059519 has 2 divisors, whose sum is σ = 81390059520. Its totient is φ = 81390059518.

The previous prime is 81390059461. The next prime is 81390059651. The reversal of 81390059519 is 91595009318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81390059519 is a prime.

It is a super-2 number, since 2×81390059519² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81390059119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40695029759 + 40695029760.

It is an arithmetic number, because the mean of its divisors is an integer number (40695029760).

Almost surely, 2^81390059519 is an apocalyptic number.

81390059519 is a deficient number, since it is larger than the sum of its proper divisors (1).

81390059519 is an equidigital number, since it uses as much as digits as its factorization.

81390059519 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 437400, while the sum is 50.

The spelling of 81390059519 in words is "eighty-one billion, three hundred ninety million, fifty-nine thousand, five hundred nineteen".