81110473957 has 2 divisors, whose sum is σ = 81110473958. Its totient is φ = 81110473956.

The previous prime is 81110473921. The next prime is 81110474017. The reversal of 81110473957 is 75937401118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60041661156 + 21068812801 = 245034^2 + 145151^2 .

It is a cyclic number.

It is not a de Polignac number, because 81110473957 - 2¹¹ = 81110471909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81110473057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40555236978 + 40555236979.

It is an arithmetic number, because the mean of its divisors is an integer number (40555236979).

Almost surely, 2^81110473957 is an apocalyptic number.

It is an amenable number.

81110473957 is a deficient number, since it is larger than the sum of its proper divisors (1).

81110473957 is an equidigital number, since it uses as much as digits as its factorization.

81110473957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 211680, while the sum is 46.

The spelling of 81110473957 in words is "eighty-one billion, one hundred ten million, four hundred seventy-three thousand, nine hundred fifty-seven".