66855387 has 8 divisors (see below), whose sum is σ = 89187840. Its totient is φ = 44546600.

The previous prime is 66855367. The next prime is 66855391. The reversal of 66855387 is 78355866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66855387 - 2¹⁹ = 66331099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66855307) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2314 + ... + 11792.

It is an arithmetic number, because the mean of its divisors is an integer number (11148480).

Almost surely, 2^66855387 is an apocalyptic number.

66855387 is a deficient number, since it is larger than the sum of its proper divisors (22332453).

66855387 is a wasteful number, since it uses less digits than its factorization.

66855387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11833.

The product of its digits is 1209600, while the sum is 48.

The square root of 66855387 is about 8176.5143551516. The cubic root of 66855387 is about 405.8623843012.

The spelling of 66855387 in words is "sixty-six million, eight hundred fifty-five thousand, three hundred eighty-seven".