64578715656 has 384 divisors, whose sum is σ = 212600505600. Its totient is φ = 15898982400.

The previous prime is 64578715631. The next prime is 64578715657. The reversal of 64578715656 is 65651787546.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 64578715656.

It is not an unprimeable number, because it can be changed into a prime (64578715657) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 60865366 + ... + 60866426.

It is an arithmetic number, because the mean of its divisors is an integer number (553647150).

Almost surely, 2^64578715656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64578715656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106300252800).

64578715656 is an abundant number, since it is smaller than the sum of its proper divisors (148021789944).

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

64578715656 is a wasteful number, since it uses less digits than its factorization.

64578715656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181 (or 1146 counting only the distinct ones).

The product of its digits is 42336000, while the sum is 60.

The spelling of 64578715656 in words is "sixty-four billion, five hundred seventy-eight million, seven hundred fifteen thousand, six hundred fifty-six".