66724280 has 96 divisors (see below), whose sum is σ = 177908400. Its totient is φ = 22450176.

The previous prime is 66724277. The next prime is 66724289. The reversal of 66724280 is 8242766.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 66724280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66724289) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 115352 + ... + 115928.

Almost surely, 2^66724280 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 66724280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88954200).

66724280 is an abundant number, since it is smaller than the sum of its proper divisors (111184120).

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

66724280 is a wasteful number, since it uses less digits than its factorization.

66724280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 66724280 is about 8168.4931290906. The cubic root of 66724280 is about 405.5969047170.

The spelling of 66724280 in words is "sixty-six million, seven hundred twenty-four thousand, two hundred eighty".