649779 has 8 divisors (see below), whose sum is σ = 933072. Its totient is φ = 399840.

The previous prime is 649777. The next prime is 649783. The reversal of 649779 is 977946.

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

It is not a de Polignac number, because 649779 - 2¹ = 649777 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 649779.

It is not an unprimeable number, because it can be changed into a prime (649771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8292 + ... + 8369.

It is an arithmetic number, because the mean of its divisors is an integer number (116634).

2⁶⁴⁹⁷⁷⁹ is an apocalyptic number.

649779 is a deficient number, since it is larger than the sum of its proper divisors (283293).

649779 is a wasteful number, since it uses less digits than its factorization.

649779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16677.

The product of its digits is 95256, while the sum is 42.

The square root of 649779 is about 806.0887047962. The cubic root of 649779 is about 86.6140920447.

The spelling of 649779 in words is "six hundred forty-nine thousand, seven hundred seventy-nine".