66440304 has 160 divisors (see below), whose sum is σ = 220938240. Its totient is φ = 18724608.

The previous prime is 66440303. The next prime is 66440357. The reversal of 66440304 is 40304466.

It is a happy number.

It is a super-2 number, since 2×66440304² = 8828627991224832, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66440303) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 383962 + ... + 384134.

It is an arithmetic number, because the mean of its divisors is an integer number (1380864).

Almost surely, 2^66440304 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 66440304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110469120).

66440304 is an abundant number, since it is smaller than the sum of its proper divisors (154497936).

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

66440304 is a wasteful number, since it uses less digits than its factorization.

66440304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 66440304 is about 8151.0921967550. The cubic root of 66440304 is about 405.0206848146.

The spelling of 66440304 in words is "sixty-six million, four hundred forty thousand, three hundred four".