66472720 has 80 divisors (see below), whose sum is σ = 168190128. Its totient is φ = 24330240.

The previous prime is 66472687. The next prime is 66472723. The reversal of 66472720 is 2727466.

66472720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 18696976 + 47775744 = 4324^2 + 6912^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (66472723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49660 + ... + 50980.

Almost surely, 2^66472720 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 66472720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84095064).

66472720 is an abundant number, since it is smaller than the sum of its proper divisors (101717408).

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

66472720 is a wasteful number, since it uses less digits than its factorization.

66472720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 66472720 is about 8153.0803994564. The cubic root of 66472720 is about 405.0865435132.

The spelling of 66472720 in words is "sixty-six million, four hundred seventy-two thousand, seven hundred twenty".