649881605 has 16 divisors (see below), whose sum is σ = 822086400. Its totient is φ = 491832000.

The previous prime is 649881599. The next prime is 649881607. The reversal of 649881605 is 506188946.

It is not a de Polignac number, because 649881605 - 2¹⁴ = 649865221 is a prime.

It is a super-2 number, since 2×649881605² = 844692201034752050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 649881605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649881607) 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, 66791 + ... + 75899.

It is an arithmetic number, because the mean of its divisors is an integer number (51380400).

Almost surely, 2^649881605 is an apocalyptic number.

It is an amenable number.

649881605 is a deficient number, since it is larger than the sum of its proper divisors (172204795).

649881605 is a wasteful number, since it uses less digits than its factorization.

649881605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9884.

The product of its (nonzero) digits is 414720, while the sum is 47.

The square root of 649881605 is about 25492.7755452403. The cubic root of 649881605 is about 866.1865081069.

The spelling of 649881605 in words is "six hundred forty-nine million, eight hundred eighty-one thousand, six hundred five".