81875870513 has 2 divisors, whose sum is σ = 81875870514. Its totient is φ = 81875870512.

The previous prime is 81875870477. The next prime is 81875870533. The reversal of 81875870513 is 31507857818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79392642289 + 2483228224 = 281767^2 + 49832^2 .

It is a cyclic number.

It is not a de Polignac number, because 81875870513 - 2²⁴ = 81859093297 is a prime.

It is not a weakly prime, because it can be changed into another prime (81875870533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40937935256 + 40937935257.

It is an arithmetic number, because the mean of its divisors is an integer number (40937935257).

Almost surely, 2^81875870513 is an apocalyptic number.

It is an amenable number.

81875870513 is a deficient number, since it is larger than the sum of its proper divisors (1).

81875870513 is an equidigital number, since it uses as much as digits as its factorization.

81875870513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1881600, while the sum is 53.

The spelling of 81875870513 in words is "eighty-one billion, eight hundred seventy-five million, eight hundred seventy thousand, five hundred thirteen".