66868538 has 16 divisors (see below), whose sum is σ = 110151360. Its totient is φ = 30192000.

The previous prime is 66868537. The next prime is 66868553. The reversal of 66868538 is 83586866.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66868537) 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, 6743 + ... + 13386.

It is an arithmetic number, because the mean of its divisors is an integer number (6884460).

Almost surely, 2^66868538 is an apocalyptic number.

66868538 is a deficient number, since it is larger than the sum of its proper divisors (43282822).

66868538 is a wasteful number, since it uses less digits than its factorization.

66868538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20293.

The product of its digits is 1658880, while the sum is 50.

The square root of 66868538 is about 8177.3185091447. The cubic root of 66868538 is about 405.8889947037. Note that the first 3 decimals are identical.

The spelling of 66868538 in words is "sixty-six million, eight hundred sixty-eight thousand, five hundred thirty-eight".