66042543840 has 1536 divisors, whose sum is σ = 296528117760. Its totient is φ = 11943936000.

The previous prime is 66042543839. The next prime is 66042543841. The reversal of 66042543840 is 4834524066.

66042543840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66042543839) and next prime (66042543841).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 66042543792 and 66042543801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66042543841) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 437367765 + ... + 437367915.

It is an arithmetic number, because the mean of its divisors is an integer number (193052160).

Almost surely, 2^66042543840 is an apocalyptic number.

66042543840 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 66042543840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148264058880).

66042543840 is an abundant number, since it is smaller than the sum of its proper divisors (230485573920).

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

66042543840 is a wasteful number, since it uses less digits than its factorization.

66042543840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 42.

The spelling of 66042543840 in words is "sixty-six billion, forty-two million, five hundred forty-three thousand, eight hundred forty".