66776800 has 36 divisors (see below), whose sum is σ = 163020816. Its totient is φ = 26710400.

The previous prime is 66776791. The next prime is 66776803. The reversal of 66776800 is 867766.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66776803) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 40936 + ... + 42535.

It is an arithmetic number, because the mean of its divisors is an integer number (4528356).

Almost surely, 2^66776800 is an apocalyptic number.

It is an amenable number.

66776800 is an abundant number, since it is smaller than the sum of its proper divisors (96244016).

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

66776800 is a wasteful number, since it uses less digits than its factorization.

66776800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83491 (or 83478 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 66776800 is about 8171.7072879540. The cubic root of 66776800 is about 405.7032945889.

It can be divided in two parts, 66776 and 800, that added together give a palindrome (67576).

The spelling of 66776800 in words is "sixty-six million, seven hundred seventy-six thousand, eight hundred".