66881857 has 8 divisors (see below), whose sum is σ = 76507200. Its totient is φ = 57274224.

The previous prime is 66881839. The next prime is 66881873. The reversal of 66881857 is 75818866.

66881857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-66881857 is a prime.

It is a super-3 number, since 3×66881857³ (a number of 24 digits) contains 333 as substring.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 66881857.

It is not an unprimeable number, because it can be changed into a prime (66881887) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5019 + ... + 12607.

It is an arithmetic number, because the mean of its divisors is an integer number (9563400).

Almost surely, 2^66881857 is an apocalyptic number.

It is an amenable number.

66881857 is a deficient number, since it is larger than the sum of its proper divisors (9625343).

66881857 is a wasteful number, since it uses less digits than its factorization.

66881857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8855.

The product of its digits is 645120, while the sum is 49.

The square root of 66881857 is about 8178.1328553650. The cubic root of 66881857 is about 405.9159414901.

The spelling of 66881857 in words is "sixty-six million, eight hundred eighty-one thousand, eight hundred fifty-seven".