66921108 has 12 divisors (see below), whose sum is σ = 156149280. Its totient is φ = 22307032.

The previous prime is 66921103. The next prime is 66921131. The reversal of 66921108 is 80112966.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66921103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2788368 + ... + 2788391.

It is an arithmetic number, because the mean of its divisors is an integer number (13012440).

Almost surely, 2^66921108 is an apocalyptic number.

It is an amenable number.

66921108 is an abundant number, since it is smaller than the sum of its proper divisors (89228172).

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

66921108 is a wasteful number, since it uses less digits than its factorization.

66921108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5576766 (or 5576764 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 66921108 is about 8180.5322565222. The cubic root of 66921108 is about 405.9953326811.

The spelling of 66921108 in words is "sixty-six million, nine hundred twenty-one thousand, one hundred eight".