66768816 has 80 divisors (see below), whose sum is σ = 181488384. Its totient is φ = 21111552.

The previous prime is 66768797. The next prime is 66768851. The reversal of 66768816 is 61886766.

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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 217335 + ... + 217641.

Almost surely, 2^66768816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66768816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90744192).

66768816 is an abundant number, since it is smaller than the sum of its proper divisors (114719568).

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

66768816 is a wasteful number, since it uses less digits than its factorization.

66768816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538 (or 532 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The square root of 66768816 is about 8171.2187585451. The cubic root of 66768816 is about 405.6871249801.

The spelling of 66768816 in words is "sixty-six million, seven hundred sixty-eight thousand, eight hundred sixteen".