66078720 has 192 divisors, whose sum is σ = 235872000. Its totient is φ = 17547264.

The previous prime is 66078709. The next prime is 66078721. The reversal of 66078720 is 2787066.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66078721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 276361 + ... + 276599.

It is an arithmetic number, because the mean of its divisors is an integer number (1228500).

Almost surely, 2^66078720 is an apocalyptic number.

66078720 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 66078720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117936000).

66078720 is an abundant number, since it is smaller than the sum of its proper divisors (169793280).

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

66078720 is a wasteful number, since it uses less digits than its factorization.

66078720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 66078720 is about 8128.8818419264. The cubic root of 66078720 is about 404.2846081323.

The spelling of 66078720 in words is "sixty-six million, seventy-eight thousand, seven hundred twenty".