66906 has 40 divisors (see below), whose sum is σ = 174240. Its totient is φ = 18792.

The previous prime is 66889. The next prime is 66919. The reversal of 66906 is 60966.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66906.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1105 + ... + 1163.

It is an arithmetic number, because the mean of its divisors is an integer number (4356).

2⁶⁶⁹⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87120).

66906 is an abundant number, since it is smaller than the sum of its proper divisors (107334).

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

66906 is a wasteful number, since it uses less digits than its factorization.

66906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 66906 is about 258.6619415376. The cubic root of 66906 is about 40.5964778101.

The spelling of 66906 in words is "sixty-six thousand, nine hundred six".