66136780800 has 624 divisors, whose sum is σ = 255952368000. Its totient is φ = 16694968320.

The previous prime is 66136780793. The next prime is 66136780823. The reversal of 66136780800 is 808763166.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52530571 + ... + 52531829.

Almost surely, 2^66136780800 is an apocalyptic number.

66136780800 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 66136780800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127976184000).

66136780800 is an abundant number, since it is smaller than the sum of its proper divisors (189815587200).

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

66136780800 is a wasteful number, since it uses less digits than its factorization.

66136780800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321 (or 1288 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 66136780800 in words is "sixty-six billion, one hundred thirty-six million, seven hundred eighty thousand, eight hundred".