66645504 has 100 divisors (see below), whose sum is σ = 199043064. Its totient is φ = 22201344.

The previous prime is 66645493. The next prime is 66645517. The reversal of 66645504 is 40554666.

It is a happy number.

66645504 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 40669 + ... + 42275.

Almost surely, 2^66645504 is an apocalyptic number.

66645504 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66645504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99521532).

66645504 is an abundant number, since it is smaller than the sum of its proper divisors (132397560).

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

66645504 is an equidigital number, since it uses as much as digits as its factorization.

66645504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1612 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 66645504 is about 8163.6697630416. The cubic root of 66645504 is about 405.4372232930.

The spelling of 66645504 in words is "sixty-six million, six hundred forty-five thousand, five hundred four".