66890880 has 384 divisors, whose sum is σ = 279072000. Its totient is φ = 15095808.

The previous prime is 66890867. The next prime is 66890891. The reversal of 66890880 is 8809866.

66890880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (384).

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

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 47 ways as a sum of consecutive naturals, for example, 846681 + ... + 846759.

It is an arithmetic number, because the mean of its divisors is an integer number (726750).

Almost surely, 2^66890880 is an apocalyptic number.

66890880 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 66890880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139536000).

66890880 is an abundant number, since it is smaller than the sum of its proper divisors (212181120).

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

66890880 is a wasteful number, since it uses less digits than its factorization.

66890880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 66890880 is about 8178.6844907968. The cubic root of 66890880 is about 405.9341946458.

The spelling of 66890880 in words is "sixty-six million, eight hundred ninety thousand, eight hundred eighty".