66409188 has 48 divisors (see below), whose sum is σ = 167287680. Its totient is φ = 20441344.

The previous prime is 66409183. The next prime is 66409201. The reversal of 66409188 is 88190466.

It is not an unprimeable number, because it can be changed into a prime (66409181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3856 + ... + 12152.

It is an arithmetic number, because the mean of its divisors is an integer number (3485160).

Almost surely, 2^66409188 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 66409188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83643840).

66409188 is an abundant number, since it is smaller than the sum of its proper divisors (100878492).

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

66409188 is a wasteful number, since it uses less digits than its factorization.

66409188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8356 (or 8354 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 66409188 is about 8149.1832719604. The cubic root of 66409188 is about 404.9574471372.

The spelling of 66409188 in words is "sixty-six million, four hundred nine thousand, one hundred eighty-eight".