66666380 has 24 divisors (see below), whose sum is σ = 152727120. Its totient is φ = 24242240.

The previous prime is 66666371. The next prime is 66666409. The reversal of 66666380 is 8366666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151295 + ... + 151734.

It is an arithmetic number, because the mean of its divisors is an integer number (6363630).

Almost surely, 2^66666380 is an apocalyptic number.

It is an amenable number.

66666380 is an abundant number, since it is smaller than the sum of its proper divisors (86060740).

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

66666380 is a wasteful number, since it uses less digits than its factorization.

66666380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303049 (or 303047 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 66666380 is about 8164.9482545819. The cubic root of 66666380 is about 405.4795518492.

The spelling of 66666380 in words is "sixty-six million, six hundred sixty-six thousand, three hundred eighty".