64655756544 has 72 divisors (see below), whose sum is σ = 172850712832. Its totient is φ = 21455216640.

The previous prime is 64655756537. The next prime is 64655756569. The reversal of 64655756544 is 44565755646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17497 + ... + 360024.

Almost surely, 2^64655756544 is an apocalyptic number.

64655756544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64655756544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86425356416).

64655756544 is an abundant number, since it is smaller than the sum of its proper divisors (108194956288).

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

64655756544 is a wasteful number, since it uses less digits than its factorization.

64655756544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377763 (or 377749 counting only the distinct ones).

The product of its digits is 60480000, while the sum is 57.

The spelling of 64655756544 in words is "sixty-four billion, six hundred fifty-five million, seven hundred fifty-six thousand, five hundred forty-four".