66778730 has 32 divisors (see below), whose sum is σ = 126956160. Its totient is φ = 25220160.

The previous prime is 66778727. The next prime is 66778753. The reversal of 66778730 is 3787766.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105515 + ... + 106145.

It is an arithmetic number, because the mean of its divisors is an integer number (3967380).

Almost surely, 2^66778730 is an apocalyptic number.

66778730 is a deficient number, since it is larger than the sum of its proper divisors (60177430).

66778730 is a wasteful number, since it uses less digits than its factorization.

66778730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214.

The product of its (nonzero) digits is 296352, while the sum is 44.

The square root of 66778730 is about 8171.8253774784. The cubic root of 66778730 is about 405.7072031311.

It can be divided in two parts, 667 and 78730, that added together give a palindrome (79397).

The spelling of 66778730 in words is "sixty-six million, seven hundred seventy-eight thousand, seven hundred thirty".