66780318 has 64 divisors (see below), whose sum is σ = 157324032. Its totient is φ = 18670080.

The previous prime is 66780317. The next prime is 66780331. The reversal of 66780318 is 81308766.

It is a super-2 number, since 2×66780318² = 8919221744362248, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66780317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58905 + ... + 60027.

It is an arithmetic number, because the mean of its divisors is an integer number (2458188).

Almost surely, 2^66780318 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66780318, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78662016).

66780318 is an abundant number, since it is smaller than the sum of its proper divisors (90543714).

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

66780318 is a wasteful number, since it uses less digits than its factorization.

66780318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1209.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 66780318 is about 8171.9225400147. The cubic root of 66780318 is about 405.7104190150.

The spelling of 66780318 in words is "sixty-six million, seven hundred eighty thousand, three hundred eighteen".