66385059840 has 1120 divisors, whose sum is σ = 277464585024. Its totient is φ = 15005122560.

The previous prime is 66385059817. The next prime is 66385059877. The reversal of 66385059840 is 4895058366.

It is a happy number.

66385059840 is a `hidden beast` number, since 6 + 6 + 3 + 8 + 5 + 0 + 598 + 40 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 620421067 + ... + 620421173.

Almost surely, 2^66385059840 is an apocalyptic number.

66385059840 is a gapful number since it is divisible by the number (60) 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 66385059840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138732292512).

66385059840 is an abundant number, since it is smaller than the sum of its proper divisors (211079525184).

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

66385059840 is a wasteful number, since it uses less digits than its factorization.

66385059840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 66385059840 in words is "sixty-six billion, three hundred eighty-five million, fifty-nine thousand, eight hundred forty".