66790656 has 90 divisors (see below), whose sum is σ = 199219482. Its totient is φ = 22256640.

The previous prime is 66790649. The next prime is 66790657. The reversal of 66790656 is 65609766.

It can be written as a sum of positive squares in only one way, i.e., 62726400 + 4064256 = 7920^2 + 2016^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66790657) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 19126 + ... + 22346.

Almost surely, 2^66790656 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 66790656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99609741).

66790656 is an abundant number, since it is smaller than the sum of its proper divisors (132428826).

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

66790656 is an equidigital number, since it uses as much as digits as its factorization.

66790656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3249 (or 3226 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 45.

The square root of 66790656 is about 8172.5550472297. Note that the first 3 decimals coincide. The cubic root of 66790656 is about 405.7313534162.

The spelling of 66790656 in words is "sixty-six million, seven hundred ninety thousand, six hundred fifty-six".