649188687 has 8 divisors (see below), whose sum is σ = 989239936. Its totient is φ = 370964952.

The previous prime is 649188677. The next prime is 649188691. The reversal of 649188687 is 786881946.

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

It is not a de Polignac number, because 649188687 - 2⁷ = 649188559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649188607) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15456853 + ... + 15456894.

It is an arithmetic number, because the mean of its divisors is an integer number (123654992).

Almost surely, 2^649188687 is an apocalyptic number.

649188687 is a deficient number, since it is larger than the sum of its proper divisors (340051249).

649188687 is a wasteful number, since it uses less digits than its factorization.

649188687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30913757.

The product of its digits is 4644864, while the sum is 57.

The square root of 649188687 is about 25479.1814428957. The cubic root of 649188687 is about 865.8785496219.

The spelling of 649188687 in words is "six hundred forty-nine million, one hundred eighty-eight thousand, six hundred eighty-seven".