649661208 has 64 divisors (see below), whose sum is σ = 1894080000. Its totient is φ = 185615136.

The previous prime is 649661183. The next prime is 649661209. The reversal of 649661208 is 802166946.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 649661208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649661209) 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 15 ways as a sum of consecutive naturals, for example, 31228 + ... + 47691.

It is an arithmetic number, because the mean of its divisors is an integer number (29595000).

Almost surely, 2^649661208 is an apocalyptic number.

It is an amenable number.

649661208 is an abundant number, since it is smaller than the sum of its proper divisors (1244418792).

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

649661208 is a wasteful number, since it uses less digits than its factorization.

649661208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78949 (or 78931 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 649661208 is about 25488.4524441952. The cubic root of 649661208 is about 866.0885792476.

The spelling of 649661208 in words is "six hundred forty-nine million, six hundred sixty-one thousand, two hundred eight".