66804100 has 54 divisors (see below), whose sum is σ = 159370442. Its totient is φ = 24288000.

The previous prime is 66804091. The next prime is 66804119. The reversal of 66804100 is 140866.

It can be written as a sum of positive squares in 3 ways, for example, as 1258884 + 65545216 = 1122^2 + 8096^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9340 + ... + 14860.

Almost surely, 2^66804100 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 66804100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79685221).

66804100 is an abundant number, since it is smaller than the sum of its proper divisors (92566342).

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

66804100 is a wasteful number, since it uses less digits than its factorization.

66804100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5557 (or 5539 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 66804100 is about 8173.3775148344. The cubic root of 66804100 is about 405.7585742217.

Adding to 66804100 its reverse (140866), we get a palindrome (66944966).

The spelling of 66804100 in words is "sixty-six million, eight hundred four thousand, one hundred".