649210905 has 96 divisors (see below), whose sum is σ = 1374796800. Its totient is φ = 276794496.

The previous prime is 649210901. The next prime is 649210921. The reversal of 649210905 is 509012946.

649210905 is a `hidden beast` number, since 649 + 2 + 1 + 0 + 9 + 0 + 5 = 666.

It is not a de Polignac number, because 649210905 - 2² = 649210901 is a prime.

It is a super-3 number, since 3×649210905³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 649210905.

It is not an unprimeable number, because it can be changed into a prime (649210901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 400186 + ... + 401804.

It is an arithmetic number, because the mean of its divisors is an integer number (14320800).

Almost surely, 2^649210905 is an apocalyptic number.

It is an amenable number.

649210905 is an abundant number, since it is smaller than the sum of its proper divisors (725585895).

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

649210905 is a wasteful number, since it uses less digits than its factorization.

649210905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1723 (or 1720 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 649210905 is about 25479.6174421831. The cubic root of 649210905 is about 865.8884275257. Note that the first 3 decimals are identical.

The spelling of 649210905 in words is "six hundred forty-nine million, two hundred ten thousand, nine hundred five".