81259502180477 has 2 divisors, whose sum is σ = 81259502180478. Its totient is φ = 81259502180476.

The previous prime is 81259502180393. The next prime is 81259502180543. The reversal of 81259502180477 is 77408120595218.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73203407698201 + 8056094482276 = 8555899^2 + 2838326^2 .

It is a cyclic number.

It is not a de Polignac number, because 81259502180477 - 2³⁰ = 81258428438653 is a prime.

It is a super-3 number, since 3×81259502180477³ (a number of 43 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81259502189477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40629751090238 + 40629751090239.

It is an arithmetic number, because the mean of its divisors is an integer number (40629751090239).

Almost surely, 2^{81259502180477} is an apocalyptic number.

It is an amenable number.

81259502180477 is a deficient number, since it is larger than the sum of its proper divisors (1).

81259502180477 is an equidigital number, since it uses as much as digits as its factorization.

81259502180477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11289600, while the sum is 59.

The spelling of 81259502180477 in words is "eighty-one trillion, two hundred fifty-nine billion, five hundred two million, one hundred eighty thousand, four hundred seventy-seven".