65810609881 has 2 divisors, whose sum is σ = 65810609882. Its totient is φ = 65810609880.

The previous prime is 65810609737. The next prime is 65810609911. The reversal of 65810609881 is 18890601856.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60257975625 + 5552634256 = 245475^2 + 74516^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65810609881 is a prime.

It is a super-2 number, since 2×65810609881² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (65810607881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32905304940 + 32905304941.

It is an arithmetic number, because the mean of its divisors is an integer number (32905304941).

Almost surely, 2^65810609881 is an apocalyptic number.

It is an amenable number.

65810609881 is a deficient number, since it is larger than the sum of its proper divisors (1).

65810609881 is an equidigital number, since it uses as much as digits as its factorization.

65810609881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 829440, while the sum is 52.

The spelling of 65810609881 in words is "sixty-five billion, eight hundred ten million, six hundred nine thousand, eight hundred eighty-one".