66856287 has 8 divisors (see below), whose sum is σ = 89192880. Its totient is φ = 44545280.

The previous prime is 66856277. The next prime is 66856297. The reversal of 66856287 is 78265866.

It is an interprime number because it is at equal distance from previous prime (66856277) and next prime (66856297).

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 66856287 - 2¹⁹ = 66331999 is a prime.

It is a super-2 number, since 2×66856287² = 8939526222852738, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66856217) by changing a digit.

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, 889 + ... + 11597.

It is an arithmetic number, because the mean of its divisors is an integer number (11149110).

Almost surely, 2^66856287 is an apocalyptic number.

66856287 is a deficient number, since it is larger than the sum of its proper divisors (22336593).

66856287 is a wasteful number, since it uses less digits than its factorization.

66856287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12793.

The product of its digits is 967680, while the sum is 48.

The square root of 66856287 is about 8176.5693906430. The cubic root of 66856287 is about 405.8642055182.

The spelling of 66856287 in words is "sixty-six million, eight hundred fifty-six thousand, two hundred eighty-seven".