66404880 has 160 divisors (see below), whose sum is σ = 232485120. Its totient is φ = 17418240.

The previous prime is 66404879. The next prime is 66404893. The reversal of 66404880 is 8840466.

66404880 is a `hidden beast` number, since 6 + 640 + 4 + 8 + 8 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153144 + ... + 153576.

It is an arithmetic number, because the mean of its divisors is an integer number (1453032).

Almost surely, 2^66404880 is an apocalyptic number.

66404880 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 66404880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116242560).

66404880 is an abundant number, since it is smaller than the sum of its proper divisors (166080240).

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

66404880 is a wasteful number, since it uses less digits than its factorization.

66404880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 514 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 66404880 is about 8148.9189467070. The cubic root of 66404880 is about 404.9486903448.

It can be divided in two parts, 664048 and 80, that added together give a triangular number (664128 = T₁₁₅₂).

The spelling of 66404880 in words is "sixty-six million, four hundred four thousand, eight hundred eighty".