649989999 has 24 divisors (see below), whose sum is σ = 952723200. Its totient is φ = 426980160.

The previous prime is 649989997. The next prime is 649990009. The reversal of 649989999 is 999989946.

It is not a de Polignac number, because 649989999 - 2¹ = 649989997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649989997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 185637 + ... + 189105.

It is an arithmetic number, because the mean of its divisors is an integer number (39696800).

Almost surely, 2^649989999 is an apocalyptic number.

649989999 is a deficient number, since it is larger than the sum of its proper divisors (302733201).

649989999 is a wasteful number, since it uses less digits than its factorization.

649989999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3775 (or 3772 counting only the distinct ones).

The product of its digits is 102036672, while the sum is 72.

The square root of 649989999 is about 25494.9014314627. The cubic root of 649989999 is about 866.2346626221.

The spelling of 649989999 in words is "six hundred forty-nine million, nine hundred eighty-nine thousand, nine hundred ninety-nine".