66444444 has 72 divisors (see below), whose sum is σ = 192890880. Its totient is φ = 19072800.

The previous prime is 66444437. The next prime is 66444461. The reversal of 66444444 is 44444466.

66444444 is a `hidden beast` number, since 6 + 644 + 4 + 4 + 4 + 4 = 666.

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

It is a nude number because it is divisible by every one of its digits.

66444444 is a modest number, since divided by 44444 gives 664 as remainder.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66444399 and 66444408.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 3109 + ... + 11939.

It is an arithmetic number, because the mean of its divisors is an integer number (2679040).

Almost surely, 2^66444444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66444444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96445440).

66444444 is an abundant number, since it is smaller than the sum of its proper divisors (126446436).

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

66444444 is a wasteful number, since it uses less digits than its factorization.

66444444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8871 (or 8866 counting only the distinct ones).

The product of its digits is 147456, while the sum is 36.

The square root of 66444444 is about 8151.3461464963. The cubic root of 66444444 is about 405.0290971322.

The spelling of 66444444 in words is "sixty-six million, four hundred forty-four thousand, four hundred forty-four".