66801693168 has 480 divisors, whose sum is σ = 229478645760. Its totient is φ = 18223833600.

The previous prime is 66801693163. The next prime is 66801693173. The reversal of 66801693168 is 86139610866.

It is an interprime number because it is at equal distance from previous prime (66801693163) and next prime (66801693173).

It is a super-2 number, since 2×66801693168² (a number of 22 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66801693163) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 369070038 + ... + 369070218.

It is an arithmetic number, because the mean of its divisors is an integer number (478080512).

Almost surely, 2^66801693168 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 66801693168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114739322880).

66801693168 is an abundant number, since it is smaller than the sum of its proper divisors (162676952592).

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

66801693168 is a wasteful number, since it uses less digits than its factorization.

66801693168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 66801693168 in words is "sixty-six billion, eight hundred one million, six hundred ninety-three thousand, one hundred sixty-eight".