81338897763973 has 2 divisors, whose sum is σ = 81338897763974. Its totient is φ = 81338897763972.

The previous prime is 81338897763953. The next prime is 81338897764027. The reversal of 81338897763973 is 37936779883318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79065850042404 + 2273047721569 = 8891898^2 + 1507663^2 .

It is a cyclic number.

It is not a de Polignac number, because 81338897763973 - 2⁵ = 81338897763941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81338897763923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40669448881986 + 40669448881987.

It is an arithmetic number, because the mean of its divisors is an integer number (40669448881987).

Almost surely, 2^{81338897763973} is an apocalyptic number.

It is an amenable number.

81338897763973 is a deficient number, since it is larger than the sum of its proper divisors (1).

81338897763973 is an equidigital number, since it uses as much as digits as its factorization.

81338897763973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6913299456, while the sum is 82.

The spelling of 81338897763973 in words is "eighty-one trillion, three hundred thirty-eight billion, eight hundred ninety-seven million, seven hundred sixty-three thousand, nine hundred seventy-three".