64776137728 has 44 divisors (see below), whose sum is σ = 131312953872. Its totient is φ = 31931863040.

The previous prime is 64776137719. The next prime is 64776137743. The reversal of 64776137728 is 82773167746.

It is a happy number.

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, 372775 + ... + 518182.

Almost surely, 2^64776137728 is an apocalyptic number.

It is an amenable number.

64776137728 is an abundant number, since it is smaller than the sum of its proper divisors (66536816144).

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

64776137728 is an equidigital number, since it uses as much as digits as its factorization.

64776137728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891048 (or 891030 counting only the distinct ones).

The product of its digits is 16595712, while the sum is 58.

The spelling of 64776137728 in words is "sixty-four billion, seven hundred seventy-six million, one hundred thirty-seven thousand, seven hundred twenty-eight".