378783666 has 24 divisors (see below), whose sum is σ = 840716604. Its totient is φ = 123181440.

The previous prime is 378783659. The next prime is 378783667. The reversal of 378783666 is 666387873.

It can be written as a sum of positive squares in 2 ways, for example, as 351000225 + 27783441 = 18735^2 + 5271^2 .

It is a super-3 number, since 3×378783666³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (378783667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 255891 + ... + 257366.

Almost surely, 2^378783666 is an apocalyptic number.

378783666 is an abundant number, since it is smaller than the sum of its proper divisors (461932938).

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

378783666 is a wasteful number, since it uses less digits than its factorization.

378783666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513306 (or 513303 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 378783666 is about 19462.3653752569. The cubic root of 378783666 is about 723.5420027460.

The spelling of 378783666 in words is "three hundred seventy-eight million, seven hundred eighty-three thousand, six hundred sixty-six".