66398800 has 90 divisors (see below), whose sum is σ = 173327882. Its totient is φ = 24299520.

The previous prime is 66398747. The next prime is 66398819. The reversal of 66398800 is 889366.

66398800 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 9 ways, for example, as 64064016 + 2334784 = 8004^2 + 1528^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

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 17 ways as a sum of consecutive naturals, for example, 587544 + ... + 587656.

Almost surely, 2^66398800 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 66398800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86663941).

66398800 is an abundant number, since it is smaller than the sum of its proper divisors (106929082).

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

66398800 is a wasteful number, since it uses less digits than its factorization.

66398800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 66398800 is about 8148.5458825486. The cubic root of 66398800 is about 404.9363309962.

The spelling of 66398800 in words is "sixty-six million, three hundred ninety-eight thousand, eight hundred".