66188774400 has 1056 divisors, whose sum is σ = 268432247808. Its totient is φ = 14057472000.

The previous prime is 66188774383. The next prime is 66188774401. The reversal of 66188774400 is 447788166.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66188774401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 655334350 + ... + 655334450.

Almost surely, 2^66188774400 is an apocalyptic number.

66188774400 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 66188774400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134216123904).

66188774400 is an abundant number, since it is smaller than the sum of its proper divisors (202243473408).

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

66188774400 is a wasteful number, since it uses less digits than its factorization.

66188774400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 51.

The spelling of 66188774400 in words is "sixty-six billion, one hundred eighty-eight million, seven hundred seventy-four thousand, four hundred".