65387778447 has 32 divisors (see below), whose sum is σ = 91942179840. Its totient is φ = 41253555200.

The previous prime is 65387778433. The next prime is 65387778451. The reversal of 65387778447 is 74487778356.

It is a cyclic number.

It is not a de Polignac number, because 65387778447 - 2¹⁰ = 65387777423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65387778647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13161958 + ... + 13166924.

It is an arithmetic number, because the mean of its divisors is an integer number (2873193120).

Almost surely, 2^65387778447 is an apocalyptic number.

65387778447 is a deficient number, since it is larger than the sum of its proper divisors (26554401393).

65387778447 is a wasteful number, since it uses less digits than its factorization.

65387778447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6983.

The product of its digits is 221276160, while the sum is 66.

Subtracting 65387778447 from its reverse (74487778356), we obtain a palindrome (9099999909).

The spelling of 65387778447 in words is "sixty-five billion, three hundred eighty-seven million, seven hundred seventy-eight thousand, four hundred forty-seven".