66857664 has 28 divisors (see below), whose sum is σ = 176894744. Its totient is φ = 22285824.

The previous prime is 66857627. The next prime is 66857683. The reversal of 66857664 is 46675866.

66857664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 173917 + ... + 174300.

Almost surely, 2^66857664 is an apocalyptic number.

66857664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66857664 is an abundant number, since it is smaller than the sum of its proper divisors (110037080).

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

66857664 is a wasteful number, since it uses less digits than its factorization.

66857664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348232 (or 348222 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 48.

The square root of 66857664 is about 8176.6535942279. The cubic root of 66857664 is about 405.8669919486.

The spelling of 66857664 in words is "sixty-six million, eight hundred fifty-seven thousand, six hundred sixty-four".