65638473881 has 2 divisors, whose sum is σ = 65638473882. Its totient is φ = 65638473880.

The previous prime is 65638473877. The next prime is 65638473889. The reversal of 65638473881 is 18837483656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64165449481 + 1473024400 = 253309^2 + 38380^2 .

It is a cyclic number.

It is not a de Polignac number, because 65638473881 - 2² = 65638473877 is a prime.

It is a super-2 number, since 2×65638473881² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65638473881.

It is not a weakly prime, because it can be changed into another prime (65638473889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32819236940 + 32819236941.

It is an arithmetic number, because the mean of its divisors is an integer number (32819236941).

Almost surely, 2^65638473881 is an apocalyptic number.

It is an amenable number.

65638473881 is a deficient number, since it is larger than the sum of its proper divisors (1).

65638473881 is an equidigital number, since it uses as much as digits as its factorization.

65638473881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23224320, while the sum is 59.

The spelling of 65638473881 in words is "sixty-five billion, six hundred thirty-eight million, four hundred seventy-three thousand, eight hundred eighty-one".