66390912 has 96 divisors (see below), whose sum is σ = 218365680. Its totient is φ = 18966528.

The previous prime is 66390911. The next prime is 66390923. The reversal of 66390912 is 21909366.

66390912 is a `hidden beast` number, since 6 + 639 + 0 + 9 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66390911) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3948 + ... + 12180.

Almost surely, 2^66390912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66390912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109182840).

66390912 is an abundant number, since it is smaller than the sum of its proper divisors (151974768).

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

66390912 is a wasteful number, since it uses less digits than its factorization.

66390912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8260 (or 8245 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 66390912 is about 8148.0618554353. The cubic root of 66390912 is about 404.9202952432.

The spelling of 66390912 in words is "sixty-six million, three hundred ninety thousand, nine hundred twelve".