66218678064 has 480 divisors, whose sum is σ = 240653597184. Its totient is φ = 17124618240.

The previous prime is 66218678033. The next prime is 66218678083. The reversal of 66218678064 is 46087681266.

66218678064 is a `hidden beast` number, since 6 + 621 + 8 + 6 + 7 + 8 + 0 + 6 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 66218678064.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 111666952 + ... + 111667544.

Almost surely, 2^66218678064 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 66218678064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120326798592).

66218678064 is an abundant number, since it is smaller than the sum of its proper divisors (174434919120).

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

66218678064 is a wasteful number, since it uses less digits than its factorization.

66218678064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007 (or 989 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The spelling of 66218678064 in words is "sixty-six billion, two hundred eighteen million, six hundred seventy-eight thousand, sixty-four".