66844866 has 64 divisors (see below), whose sum is σ = 154791936. Its totient is φ = 19051200.

The previous prime is 66844861. The next prime is 66844879.

66844866 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×66844866² = 8936472221115912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66844861) 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, 75261 + ... + 76143.

It is an arithmetic number, because the mean of its divisors is an integer number (2418624).

Almost surely, 2^66844866 is an apocalyptic number.

66844866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66844866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77395968).

66844866 is an abundant number, since it is smaller than the sum of its proper divisors (87947070).

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

66844866 is a wasteful number, since it uses less digits than its factorization.

66844866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967.

The product of its digits is 1327104, while the sum is 48.

The square root of 66844866 is about 8175.8709627782. The cubic root of 66844866 is about 405.8410930618.

The spelling of 66844866 in words is "sixty-six million, eight hundred forty-four thousand, eight hundred sixty-six".