66385800 has 144 divisors (see below), whose sum is σ = 240179940. Its totient is φ = 16335360.

The previous prime is 66385793. The next prime is 66385801. The reversal of 66385800 is 858366.

It can be written as a sum of positive squares in 6 ways, for example, as 1454436 + 64931364 = 1206^2 + 8058^2 .

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

It is not an unprimeable number, because it can be changed into a prime (66385801) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 21982 + ... + 24818.

Almost surely, 2^66385800 is an apocalyptic number.

66385800 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 66385800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120089970).

66385800 is an abundant number, since it is smaller than the sum of its proper divisors (173794140).

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

66385800 is a wasteful number, since it uses less digits than its factorization.

66385800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2872 (or 2860 counting only the distinct ones).

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

The square root of 66385800 is about 8147.7481551653. The cubic root of 66385800 is about 404.9099022260.

The spelling of 66385800 in words is "sixty-six million, three hundred eighty-five thousand, eight hundred".