66645500 has 48 divisors (see below), whose sum is σ = 149149728. Its totient is φ = 26000000.

The previous prime is 66645493. The next prime is 66645517. The reversal of 66645500 is 554666.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 18875 + ... + 22125.

It is an arithmetic number, because the mean of its divisors is an integer number (3107286).

Almost surely, 2^66645500 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 66645500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74574864).

66645500 is an abundant number, since it is smaller than the sum of its proper divisors (82504228).

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

66645500 is a wasteful number, since it uses less digits than its factorization.

66645500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3311 (or 3299 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 66645500 is about 8163.6695180538. The cubic root of 66645500 is about 405.4372151817.

The spelling of 66645500 in words is "sixty-six million, six hundred forty-five thousand, five hundred".