66005940 has 288 divisors, whose sum is σ = 254185344. Its totient is φ = 12579840.

The previous prime is 66005923. The next prime is 66005959. The reversal of 66005940 is 4950066.

It is a Harshad number since it is a multiple of its sum of digits (30).

66005940 is a modest number, since divided by 5940 gives 660 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 66005898 and 66005907.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 420342 + ... + 420498.

It is an arithmetic number, because the mean of its divisors is an integer number (882588).

Almost surely, 2^66005940 is an apocalyptic number.

66005940 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 66005940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127092672).

66005940 is an abundant number, since it is smaller than the sum of its proper divisors (188179404).

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

66005940 is a wasteful number, since it uses less digits than its factorization.

66005940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 66005940 is about 8124.4039781390. The cubic root of 66005940 is about 404.1361254186.

The spelling of 66005940 in words is "sixty-six million, five thousand, nine hundred forty".