64545781608 has 512 divisors, whose sum is σ = 234026496000. Its totient is φ = 15996165120.

The previous prime is 64545781607. The next prime is 64545781609. The reversal of 64545781608 is 80618754546.

64545781608 is a `hidden beast` number, since 6 + 4 + 5 + 4 + 578 + 1 + 60 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (64545781607) and next prime (64545781609).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (64545781607) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 32614363 + ... + 32616341.

It is an arithmetic number, because the mean of its divisors is an integer number (457083000).

Almost surely, 2^64545781608 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 64545781608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117013248000).

64545781608 is an abundant number, since it is smaller than the sum of its proper divisors (169480714392).

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

64545781608 is a wasteful number, since it uses less digits than its factorization.

64545781608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102 (or 2092 counting only the distinct ones).

The product of its (nonzero) digits is 6451200, while the sum is 54.

The spelling of 64545781608 in words is "sixty-four billion, five hundred forty-five million, seven hundred eighty-one thousand, six hundred eight".