66320550 has 72 divisors (see below), whose sum is σ = 179144784. Its totient is φ = 17590080.

The previous prime is 66320537. The next prime is 66320557. The reversal of 66320550 is 5502366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66320557) 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 35 ways as a sum of consecutive naturals, for example, 131599 + ... + 132101.

It is an arithmetic number, because the mean of its divisors is an integer number (2488122).

Almost surely, 2^66320550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66320550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89572392).

66320550 is an abundant number, since it is smaller than the sum of its proper divisors (112824234).

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

66320550 is a wasteful number, since it uses less digits than its factorization.

66320550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 806 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 66320550 is about 8143.7429969272. The cubic root of 66320550 is about 404.7771979832. Note that the first 3 decimals are identical.

The spelling of 66320550 in words is "sixty-six million, three hundred twenty thousand, five hundred fifty".