664838672266 has 4 divisors (see below), whose sum is σ = 997258008402. Its totient is φ = 332419336132.

The previous prime is 664838672243. The next prime is 664838672269. The reversal of 664838672266 is 662276838466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 662276838466 = 2 ⋅331138419233.

It can be written as a sum of positive squares in only one way, i.e., 499242578041 + 165596094225 = 706571^2 + 406935^2 .

It is a junction number, because it is equal to n+sod(n) for n = 664838672198 and 664838672207.

It is not an unprimeable number, because it can be changed into a prime (664838672269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166209668065 + ... + 166209668068.

Almost surely, 2^664838672266 is an apocalyptic number.

664838672266 is a deficient number, since it is larger than the sum of its proper divisors (332419336136).

664838672266 is a wasteful number, since it uses less digits than its factorization.

664838672266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332419336135.

The product of its digits is 167215104, while the sum is 64.

The spelling of 664838672266 in words is "six hundred sixty-four billion, eight hundred thirty-eight million, six hundred seventy-two thousand, two hundred sixty-six".