66490880 has 80 divisors (see below), whose sum is σ = 167935680. Its totient is φ = 25178112.

The previous prime is 66490873. The next prime is 66490891. The reversal of 66490880 is 8809466.

It is a tau number, because it is divible by the number of its divisors (80).

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 7 ways as a sum of consecutive naturals, for example, 47957 + ... + 49323.

It is an arithmetic number, because the mean of its divisors is an integer number (2099196).

Almost surely, 2^66490880 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 66490880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83967840).

66490880 is an abundant number, since it is smaller than the sum of its proper divisors (101444800).

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

66490880 is a wasteful number, since it uses less digits than its factorization.

66490880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409 (or 1393 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 66490880 is about 8154.1940128991. The cubic root of 66490880 is about 405.1234293306.

The spelling of 66490880 in words is "sixty-six million, four hundred ninety thousand, eight hundred eighty".