66820669784064 has 1200 divisors, whose sum is σ = 241070415505920. Its totient is φ = 18018144092160.

The previous prime is 66820669784059. The next prime is 66820669784107. The reversal of 66820669784064 is 46048796602866.

66820669784064 is a `hidden beast` number, since 6 + 6 + 8 + 206 + 6 + 9 + 7 + 8 + 406 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 66820669783983 and 66820669784001.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 61247176159 + ... + 61247177249.

Almost surely, 2^{66820669784064} is an apocalyptic number.

66820669784064 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 66820669784064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120535207752960).

66820669784064 is an abundant number, since it is smaller than the sum of its proper divisors (174249745721856).

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

66820669784064 is a wasteful number, since it uses less digits than its factorization.

66820669784064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1504 (or 1469 counting only the distinct ones).

The product of its (nonzero) digits is 1003290624, while the sum is 72.

The spelling of 66820669784064 in words is "sixty-six trillion, eight hundred twenty billion, six hundred sixty-nine million, seven hundred eighty-four thousand, sixty-four".