649899818 has 8 divisors (see below), whose sum is σ = 975716580. Its totient is φ = 324660960.

The previous prime is 649899787. The next prime is 649899839. The reversal of 649899818 is 818998946.

It can be written as a sum of positive squares in 2 ways, for example, as 512705449 + 137194369 = 22643^2 + 11713^2 .

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

It is a Curzon 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 3 ways as a sum of consecutive naturals, for example, 141653 + ... + 146168.

Almost surely, 2^649899818 is an apocalyptic number.

649899818 is a deficient number, since it is larger than the sum of its proper divisors (325816762).

649899818 is a wasteful number, since it uses less digits than its factorization.

649899818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288952.

The product of its digits is 8957952, while the sum is 62.

The square root of 649899818 is about 25493.1327615890. The cubic root of 649899818 is about 866.1945996871.

The spelling of 649899818 in words is "six hundred forty-nine million, eight hundred ninety-nine thousand, eight hundred eighteen".