66389760 has 288 divisors, whose sum is σ = 251657280. Its totient is φ = 16515072.

The previous prime is 66389759. The next prime is 66389773. The reversal of 66389760 is 6798366.

66389760 is a `hidden beast` number, since 6 + 638 + 9 + 7 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 587464 + ... + 587576.

It is an arithmetic number, because the mean of its divisors is an integer number (873810).

Almost surely, 2^66389760 is an apocalyptic number.

66389760 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 66389760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125828640).

66389760 is an abundant number, since it is smaller than the sum of its proper divisors (185267520).

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

66389760 is a wasteful number, since it uses less digits than its factorization.

66389760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 66389760 is about 8147.9911634709. The cubic root of 66389760 is about 404.9179532014.

The spelling of 66389760 in words is "sixty-six million, three hundred eighty-nine thousand, seven hundred sixty".