66464138768 has 20 divisors (see below), whose sum is σ = 129441499068. Its totient is φ = 33059880960.

The previous prime is 66464138759. The next prime is 66464138789. The reversal of 66464138768 is 86783146466.

It can be written as a sum of positive squares in 2 ways, for example, as 4309659904 + 62154478864 = 65648^2 + 249308^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10758593 + ... + 10764768.

Almost surely, 2^66464138768 is an apocalyptic number.

It is an amenable number.

66464138768 is a deficient number, since it is larger than the sum of its proper divisors (62977360300).

66464138768 is a wasteful number, since it uses less digits than its factorization.

66464138768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21523562 (or 21523556 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 59.

It can be divided in two parts, 6646 and 4138768, that added together give a palindrome (4145414).

The spelling of 66464138768 in words is "sixty-six billion, four hundred sixty-four million, one hundred thirty-eight thousand, seven hundred sixty-eight".