66788320 has 48 divisors (see below), whose sum is σ = 164656800. Its totient is φ = 25552384.

The previous prime is 66788299. The next prime is 66788369. The reversal of 66788320 is 2388766.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5395 + ... + 12754.

It is an arithmetic number, because the mean of its divisors is an integer number (3430350).

Almost surely, 2^66788320 is an apocalyptic number.

It is an amenable number.

66788320 is an abundant number, since it is smaller than the sum of its proper divisors (97868480).

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

66788320 is a wasteful number, since it uses less digits than its factorization.

66788320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18187 (or 18179 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 66788320 is about 8172.4121286191. The cubic root of 66788320 is about 405.7266232161.

The spelling of 66788320 in words is "sixty-six million, seven hundred eighty-eight thousand, three hundred twenty".