668835538794 has 80 divisors (see below), whose sum is σ = 1523148731808. Its totient is φ = 219315415968.

The previous prime is 668835538757. The next prime is 668835538859. The reversal of 668835538794 is 497835538866.

It is a happy number.

668835538794 is a `hidden beast` number, since 6 + 6 + 8 + 83 + 5 + 538 + 7 + 9 + 4 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7913949 + ... + 7998015.

Almost surely, 2^668835538794 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668835538794, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (761574365904).

668835538794 is an abundant number, since it is smaller than the sum of its proper divisors (854313193014).

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

668835538794 is a wasteful number, since it uses less digits than its factorization.

668835538794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84881 (or 84872 counting only the distinct ones).

The product of its digits is 1045094400, while the sum is 72.

Adding to 668835538794 its sum of digits (72), we get a palindrome (668835538866).

The spelling of 668835538794 in words is "six hundred sixty-eight billion, eight hundred thirty-five million, five hundred thirty-eight thousand, seven hundred ninety-four".