666138322 has 4 divisors (see below), whose sum is σ = 999207486. Its totient is φ = 333069160.

The previous prime is 666138299. The next prime is 666138367. The reversal of 666138322 is 223831666.

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., 350400961 + 315737361 = 18719^2 + 17769^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 166534579 + ... + 166534582.

Almost surely, 2^666138322 is an apocalyptic number.

666138322 is a deficient number, since it is larger than the sum of its proper divisors (333069164).

666138322 is a wasteful number, since it uses less digits than its factorization.

666138322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333069163.

The product of its digits is 62208, while the sum is 37.

The square root of 666138322 is about 25809.6555963074. The cubic root of 666138322 is about 873.3496279551.

Adding to 666138322 its reverse (223831666), we get a palindrome (889969988).

The spelling of 666138322 in words is "six hundred sixty-six million, one hundred thirty-eight thousand, three hundred twenty-two".