66442783680 has 1120 divisors, whose sum is σ = 308187766656. Its totient is φ = 13186105344.

The previous prime is 66442783651. The next prime is 66442783733. The reversal of 66442783680 is 8638724466.

66442783680 is a `hidden beast` number, since 6 + 6 + 4 + 4 + 278 + 368 + 0 = 666.

66442783680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (1120).

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 159 ways as a sum of consecutive naturals, for example, 40097412 + ... + 40099068.

Almost surely, 2^66442783680 is an apocalyptic number.

66442783680 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 66442783680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154093883328).

66442783680 is an abundant number, since it is smaller than the sum of its proper divisors (241744982976).

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

66442783680 is a wasteful number, since it uses less digits than its factorization.

66442783680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1723 (or 1704 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 54.

The spelling of 66442783680 in words is "sixty-six billion, four hundred forty-two million, seven hundred eighty-three thousand, six hundred eighty".