66778260361344 has 1792 divisors, whose sum is σ = 255142756915200. Its totient is φ = 16940203868160.

The previous prime is 66778260361291. The next prime is 66778260361369. The reversal of 66778260361344 is 44316306287766.

66778260361344 is a `hidden beast` number, since 6 + 6 + 7 + 7 + 8 + 2 + 6 + 0 + 3 + 613 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 64770378109 + ... + 64770379139.

It is an arithmetic number, because the mean of its divisors is an integer number (142378770600).

Almost surely, 2^{66778260361344} is an apocalyptic number.

66778260361344 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 66778260361344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127571378457600).

66778260361344 is an abundant number, since it is smaller than the sum of its proper divisors (188364496553856).

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

66778260361344 is a wasteful number, since it uses less digits than its factorization.

66778260361344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1413 (or 1386 counting only the distinct ones).

The product of its (nonzero) digits is 146313216, while the sum is 63.

The spelling of 66778260361344 in words is "sixty-six trillion, seven hundred seventy-eight billion, two hundred sixty million, three hundred sixty-one thousand, three hundred forty-four".