666972794 has 4 divisors (see below), whose sum is σ = 1000459194. Its totient is φ = 333486396.

The previous prime is 666972773. The next prime is 666972797. The reversal of 666972794 is 497279666.

666972794 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 525005569 + 141967225 = 22913^2 + 11915^2 .

It is not an unprimeable number, because it can be changed into a prime (666972797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166743197 + ... + 166743200.

Almost surely, 2^666972794 is an apocalyptic number.

666972794 is a deficient number, since it is larger than the sum of its proper divisors (333486400).

666972794 is a wasteful number, since it uses less digits than its factorization.

666972794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333486399.

The product of its digits is 6858432, while the sum is 56.

The square root of 666972794 is about 25825.8164246554. The cubic root of 666972794 is about 873.7141577039.

It can be divided in two parts, 666972 and 794, that added together give a palindrome (667766).

The spelling of 666972794 in words is "six hundred sixty-six million, nine hundred seventy-two thousand, seven hundred ninety-four".