649021684617216 has 819 divisors, whose sum is σ = 2037400142091097. Its totient is φ = 206611619512320.

The previous prime is 649021684617199. The next prime is 649021684617227. The reversal of 649021684617216 is 612716486120946.

The square root of 649021684617216 is 25475904.

It is a perfect power (a square), and thus also a powerful number.

649021684617216 is a `hidden beast` number, since 6 + 4 + 9 + 0 + 2 + 1 + 6 + 8 + 4 + 617 + 2 + 1 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 585838263177216 + 63183421440000 = 24204096^2 + 7948800^2 .

It is a Duffinian number.

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 in 62 ways as a sum of consecutive naturals, for example, 1012514328256 + ... + 1012514328896.

Almost surely, 2^{649021684617216} is an apocalyptic number.

649021684617216 is the 25475904-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649021684617216

649021684617216 is an abundant number, since it is smaller than the sum of its proper divisors (1388378457473881).

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

649021684617216 is an frugal number, since it uses more digits than its factorization.

649021684617216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 41803776, while the sum is 63.

The spelling of 649021684617216 in words is "six hundred forty-nine trillion, twenty-one billion, six hundred eighty-four million, six hundred seventeen thousand, two hundred sixteen".