66720750 has 64 divisors (see below), whose sum is σ = 176364864. Its totient is φ = 16742400.

The previous prime is 66720743. The next prime is 66720751. The reversal of 66720750 is 5702766.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66720751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10134 + ... + 15366.

It is an arithmetic number, because the mean of its divisors is an integer number (2755701).

Almost surely, 2^66720750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66720750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88182432).

66720750 is an abundant number, since it is smaller than the sum of its proper divisors (109644114).

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

66720750 is a wasteful number, since it uses less digits than its factorization.

66720750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5270 (or 5260 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 33.

The square root of 66720750 is about 8168.2770521084. The cubic root of 66720750 is about 405.5897519868.

The spelling of 66720750 in words is "sixty-six million, seven hundred twenty thousand, seven hundred fifty".