64660778508 has 48 divisors (see below), whose sum is σ = 159058045440. Its totient is φ = 20403930624.

The previous prime is 64660778503. The next prime is 64660778521. The reversal of 64660778508 is 80587706646.

It is not an unprimeable number, because it can be changed into a prime (64660778503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1180848 + ... + 1234391.

It is an arithmetic number, because the mean of its divisors is an integer number (3313709280).

Almost surely, 2^64660778508 is an apocalyptic number.

It is an amenable number.

64660778508 is an abundant number, since it is smaller than the sum of its proper divisors (94397266932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64660778508 is a wasteful number, since it uses less digits than its factorization.

64660778508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2415366 (or 2415364 counting only the distinct ones).

The product of its (nonzero) digits is 13547520, while the sum is 57.

The spelling of 64660778508 in words is "sixty-four billion, six hundred sixty million, seven hundred seventy-eight thousand, five hundred eight".