81877226149717 has 2 divisors, whose sum is σ = 81877226149718. Its totient is φ = 81877226149716.

The previous prime is 81877226149703. The next prime is 81877226149721. The reversal of 81877226149717 is 71794162277818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75106332964881 + 6770893184836 = 8666391^2 + 2602094^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81877226149717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81877226149777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40938613074858 + 40938613074859.

It is an arithmetic number, because the mean of its divisors is an integer number (40938613074859).

Almost surely, 2^{81877226149717} is an apocalyptic number.

It is an amenable number.

81877226149717 is a deficient number, since it is larger than the sum of its proper divisors (1).

81877226149717 is an equidigital number, since it uses as much as digits as its factorization.

81877226149717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132765696, while the sum is 70.

The spelling of 81877226149717 in words is "eighty-one trillion, eight hundred seventy-seven billion, two hundred twenty-six million, one hundred forty-nine thousand, seven hundred seventeen".