666478080 has 120 divisors (see below), whose sum is σ = 2308280832. Its totient is φ = 177721344.

The previous prime is 666478079. The next prime is 666478117. The reversal of 666478080 is 80874666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×666478080² = 888386062240972800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 11 ways as a sum of consecutive naturals, for example, 8577 + ... + 37503.

Almost surely, 2^666478080 is an apocalyptic number.

666478080 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 666478080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1154140416).

666478080 is an abundant number, since it is smaller than the sum of its proper divisors (1641802752).

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

666478080 is a wasteful number, since it uses less digits than its factorization.

666478080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28956 (or 28937 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 666478080 is about 25816.2367513160. The cubic root of 666478080 is about 873.4980841539.

The spelling of 666478080 in words is "six hundred sixty-six million, four hundred seventy-eight thousand, eighty".