66645000 has 120 divisors (see below), whose sum is σ = 225701190. Its totient is φ = 17760000.

The previous prime is 66644999. The next prime is 66645031. The reversal of 66645000 is 54666.

66645000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 5 ways, for example, as 352836 + 66292164 = 594^2 + 8142^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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 29 ways as a sum of consecutive naturals, for example, 44260 + ... + 45740.

Almost surely, 2^66645000 is an apocalyptic number.

66645000 is a gapful number since it is divisible by the number (60) 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 66645000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112850595).

66645000 is an abundant number, since it is smaller than the sum of its proper divisors (159056190).

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

66645000 is a wasteful number, since it uses less digits than its factorization.

66645000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1513 (or 1491 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 66645000 is about 8163.6388945127. The cubic root of 66645000 is about 405.4362012642.

Adding to 66645000 its reverse (54666), we get a palindrome (66699666).

It can be divided in two parts, 6664 and 5000, that added together give a square (11664 = 108²).

The spelling of 66645000 in words is "sixty-six million, six hundred forty-five thousand".