66784509506400 has 1152 divisors, whose sum is σ = 268816394649600. Its totient is φ = 14345920512000.

The previous prime is 66784509506399. The next prime is 66784509506411. The reversal of 66784509506400 is 460590548766.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10649735265 + ... + 10649741535.

It is an arithmetic number, because the mean of its divisors is an integer number (233347564800).

Almost surely, 2^{66784509506400} is an apocalyptic number.

66784509506400 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 66784509506400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134408197324800).

66784509506400 is an abundant number, since it is smaller than the sum of its proper divisors (202031885143200).

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

66784509506400 is a wasteful number, since it uses less digits than its factorization.

66784509506400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7093 (or 7066 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 60.

The spelling of 66784509506400 in words is "sixty-six trillion, seven hundred eighty-four billion, five hundred nine million, five hundred six thousand, four hundred".