666194478 has 8 divisors (see below), whose sum is σ = 1332388968. Its totient is φ = 222064824.

The previous prime is 666194443. The next prime is 666194479. The reversal of 666194478 is 874491666.

It is a sphenic number, since it is the product of 3 distinct primes.

666194478 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 666194478.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666194479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55516201 + ... + 55516212.

It is an arithmetic number, because the mean of its divisors is an integer number (166548621).

Almost surely, 2^666194478 is an apocalyptic number.

666194478 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

666194478 is a wasteful number, since it uses less digits than its factorization.

666194478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111032418.

The product of its digits is 1741824, while the sum is 51.

The square root of 666194478 is about 25810.7434608149. The cubic root of 666194478 is about 873.3741686259.

The spelling of 666194478 in words is "six hundred sixty-six million, one hundred ninety-four thousand, four hundred seventy-eight".