81427300787501 has 2 divisors, whose sum is σ = 81427300787502. Its totient is φ = 81427300787500.

The previous prime is 81427300787491. The next prime is 81427300787641. The reversal of 81427300787501 is 10578700372418.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78760317839401 + 2666982948100 = 8874701^2 + 1633090^2 .

It is a cyclic number.

It is not a de Polignac number, because 81427300787501 - 2³⁴ = 81410120918317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81427300787801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40713650393750 + 40713650393751.

It is an arithmetic number, because the mean of its divisors is an integer number (40713650393751).

Almost surely, 2^{81427300787501} is an apocalyptic number.

It is an amenable number.

81427300787501 is a deficient number, since it is larger than the sum of its proper divisors (1).

81427300787501 is an equidigital number, since it uses as much as digits as its factorization.

81427300787501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2634240, while the sum is 53.

The spelling of 81427300787501 in words is "eighty-one trillion, four hundred twenty-seven billion, three hundred million, seven hundred eighty-seven thousand, five hundred one".