66659880 has 64 divisors (see below), whose sum is σ = 228551040. Its totient is φ = 15236352.

The previous prime is 66659869. The next prime is 66659897. The reversal of 66659880 is 8895666.

66659880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66659880² = 8887079203228800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

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 15 ways as a sum of consecutive naturals, for example, 38839 + ... + 40518.

It is an arithmetic number, because the mean of its divisors is an integer number (3571110).

Almost surely, 2^66659880 is an apocalyptic number.

66659880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66659880 is an abundant number, since it is smaller than the sum of its proper divisors (161891160).

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

66659880 is a wasteful number, since it uses less digits than its factorization.

66659880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79378 (or 79374 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 48.

The square root of 66659880 is about 8164.5502019401. The cubic root of 66659880 is about 405.4663732788.

The spelling of 66659880 in words is "sixty-six million, six hundred fifty-nine thousand, eight hundred eighty".