649533521666 has 8 divisors (see below), whose sum is σ = 974336811024. Its totient is φ = 324754584660.

The previous prime is 649533521627. The next prime is 649533521669. The reversal of 649533521666 is 666125335946.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (649533521669) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6021260 + ... + 6128183.

It is an arithmetic number, because the mean of its divisors is an integer number (121792101378).

Almost surely, 2^649533521666 is an apocalyptic number.

649533521666 is a deficient number, since it is larger than the sum of its proper divisors (324803289358).

649533521666 is a wasteful number, since it uses less digits than its factorization.

649533521666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12176176.

The product of its digits is 20995200, while the sum is 56.

The spelling of 649533521666 in words is "six hundred forty-nine billion, five hundred thirty-three million, five hundred twenty-one thousand, six hundred sixty-six".