81272899290697 has 2 divisors, whose sum is σ = 81272899290698. Its totient is φ = 81272899290696.

The previous prime is 81272899290683. The next prime is 81272899290721. The reversal of 81272899290697 is 79609299827218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81058762653696 + 214136637001 = 9003264^2 + 462749^2 .

It is a cyclic number.

It is not a de Polignac number, because 81272899290697 - 2²³ = 81272890902089 is a prime.

It is not a weakly prime, because it can be changed into another prime (81272899290097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40636449645348 + 40636449645349.

It is an arithmetic number, because the mean of its divisors is an integer number (40636449645349).

Almost surely, 2^{81272899290697} is an apocalyptic number.

It is an amenable number.

81272899290697 is a deficient number, since it is larger than the sum of its proper divisors (1).

81272899290697 is an equidigital number, since it uses as much as digits as its factorization.

81272899290697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987614208, while the sum is 79.

The spelling of 81272899290697 in words is "eighty-one trillion, two hundred seventy-two billion, eight hundred ninety-nine million, two hundred ninety thousand, six hundred ninety-seven".