66956800 has 60 divisors (see below), whose sum is σ = 165922416. Its totient is φ = 26777600.

The previous prime is 66956797. The next prime is 66956801. The reversal of 66956800 is 865966.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66956801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10185 + ... + 15415.

Almost surely, 2^66956800 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 66956800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82961208).

66956800 is an abundant number, since it is smaller than the sum of its proper divisors (98965616).

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

66956800 is an equidigital number, since it uses as much as digits as its factorization.

66956800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5259 (or 5238 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 66956800 is about 8182.7134863687. The cubic root of 66956800 is about 406.0674983023.

The spelling of 66956800 in words is "sixty-six million, nine hundred fifty-six thousand, eight hundred".