81037517273 has 2 divisors, whose sum is σ = 81037517274. Its totient is φ = 81037517272.

The previous prime is 81037517257. The next prime is 81037517279. The reversal of 81037517273 is 37271573018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80231695504 + 805821769 = 283252^2 + 28387^2 .

It is a cyclic number.

It is not a de Polignac number, because 81037517273 - 2⁴ = 81037517257 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81037517279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40518758636 + 40518758637.

It is an arithmetic number, because the mean of its divisors is an integer number (40518758637).

Almost surely, 2^81037517273 is an apocalyptic number.

It is an amenable number.

81037517273 is a deficient number, since it is larger than the sum of its proper divisors (1).

81037517273 is an equidigital number, since it uses as much as digits as its factorization.

81037517273 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 246960, while the sum is 44.

The spelling of 81037517273 in words is "eighty-one billion, thirty-seven million, five hundred seventeen thousand, two hundred seventy-three".