66917760 has 256 divisors, whose sum is σ = 263208960. Its totient is φ = 14082048.

The previous prime is 66917743. The next prime is 66917777. The reversal of 66917760 is 6771966.

66917760 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66917743) and next prime (66917777).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 174529 + ... + 174911.

It is an arithmetic number, because the mean of its divisors is an integer number (1028160).

Almost surely, 2^66917760 is an apocalyptic number.

66917760 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 66917760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131604480).

66917760 is an abundant number, since it is smaller than the sum of its proper divisors (196291200).

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

66917760 is a wasteful number, since it uses less digits than its factorization.

66917760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 42.

The square root of 66917760 is about 8180.3276218010. The cubic root of 66917760 is about 405.9885620468.

The spelling of 66917760 in words is "sixty-six million, nine hundred seventeen thousand, seven hundred sixty".