666197826 has 24 divisors (see below), whose sum is σ = 1549930320. Its totient is φ = 190342152.

The previous prime is 666197813. The next prime is 666197827. The reversal of 666197826 is 628791666.

It is not an unprimeable number, because it can be changed into a prime (666197827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1132696 + ... + 1133283.

It is an arithmetic number, because the mean of its divisors is an integer number (64580430).

Almost surely, 2^666197826 is an apocalyptic number.

666197826 is an abundant number, since it is smaller than the sum of its proper divisors (883732494).

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

666197826 is a wasteful number, since it uses less digits than its factorization.

666197826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265998 (or 2265991 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 51.

The square root of 666197826 is about 25810.8083174472. The cubic root of 666197826 is about 873.3756316880.

The spelling of 666197826 in words is "six hundred sixty-six million, one hundred ninety-seven thousand, eight hundred twenty-six".