66744720 has 480 divisors, whose sum is σ = 292481280. Its totient is φ = 13271040.

The previous prime is 66744719. The next prime is 66744731. The reversal of 66744720 is 2744766.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1627900 + ... + 1627940.

It is an arithmetic number, because the mean of its divisors is an integer number (609336).

Almost surely, 2^66744720 is an apocalyptic number.

66744720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66744720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146240640).

66744720 is an abundant number, since it is smaller than the sum of its proper divisors (225736560).

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

66744720 is a wasteful number, since it uses less digits than its factorization.

66744720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 36.

The square root of 66744720 is about 8169.7441820414. The cubic root of 66744720 is about 405.6383167004.

The spelling of 66744720 in words is "sixty-six million, seven hundred forty-four thousand, seven hundred twenty".