66538800 has 240 divisors, whose sum is σ = 243094560. Its totient is φ = 17280000.

The previous prime is 66538763. The next prime is 66538819. The reversal of 66538800 is 883566.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 658750 + ... + 658850.

It is an arithmetic number, because the mean of its divisors is an integer number (1012894).

Almost surely, 2^66538800 is an apocalyptic number.

66538800 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 66538800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121547280).

66538800 is an abundant number, since it is smaller than the sum of its proper divisors (176555760).

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

66538800 is a wasteful number, since it uses less digits than its factorization.

66538800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 66538800 is about 8157.1318488792. The cubic root of 66538800 is about 405.2207301575.

The spelling of 66538800 in words is "sixty-six million, five hundred thirty-eight thousand, eight hundred".