66383516121664 has 315 divisors, whose sum is σ = 159632123992797. Its totient is φ = 27310260569088.

The previous prime is 66383516121661. The next prime is 66383516121673. The reversal of 66383516121664 is 46612161538366.

It is a happy number.

The square root of 66383516121664 is 8147608.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 4273481217600 + 62110034904064 = 2067240^2 + 7880992^2 .

It is a super-3 number, since 3×66383516121664³ (a number of 42 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (58).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66383516121599 and 66383516121608.

It is not an unprimeable number, because it can be changed into a prime (66383516121661) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 383719746282 + ... + 383719746454.

Almost surely, 2^{66383516121664} is an apocalyptic number.

66383516121664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

66383516121664 is the 8147608-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66383516121664

66383516121664 is an abundant number, since it is smaller than the sum of its proper divisors (93248607871133).

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

66383516121664 is an frugal number, since it uses more digits than its factorization.

66383516121664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488 (or 211 counting only the distinct ones).

The product of its digits is 22394880, while the sum is 58.

The spelling of 66383516121664 in words is "sixty-six trillion, three hundred eighty-three billion, five hundred sixteen million, one hundred twenty-one thousand, six hundred sixty-four".