66447765504 has 520 divisors, whose sum is σ = 213128509440. Its totient is φ = 20567457792.

The previous prime is 66447765473. The next prime is 66447765521. The reversal of 66447765504 is 40556774466.

66447765504 is a `hidden beast` number, since 6 + 6 + 4 + 4 + 77 + 65 + 504 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 523210689 + ... + 523210815.

Almost surely, 2^66447765504 is an apocalyptic number.

66447765504 is a gapful number since it is divisible by the number (64) 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 66447765504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106564254720).

66447765504 is an abundant number, since it is smaller than the sum of its proper divisors (146680743936).

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

66447765504 is a wasteful number, since it uses less digits than its factorization.

66447765504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 16934400, while the sum is 54.

The spelling of 66447765504 in words is "sixty-six billion, four hundred forty-seven million, seven hundred sixty-five thousand, five hundred four".