66855388 has 12 divisors (see below), whose sum is σ = 122083920. Its totient is φ = 31974272.

The previous prime is 66855367. The next prime is 66855391. The reversal of 66855388 is 88355866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363253 + ... + 363436.

It is an arithmetic number, because the mean of its divisors is an integer number (10173660).

Almost surely, 2^66855388 is an apocalyptic number.

It is an amenable number.

66855388 is a deficient number, since it is larger than the sum of its proper divisors (55228532).

66855388 is a wasteful number, since it uses less digits than its factorization.

66855388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726716 (or 726714 counting only the distinct ones).

The product of its digits is 1382400, while the sum is 49.

The square root of 66855388 is about 8176.5144163023. The cubic root of 66855388 is about 405.8623863248.

The spelling of 66855388 in words is "sixty-six million, eight hundred fifty-five thousand, three hundred eighty-eight".