649569 has 4 divisors (see below), whose sum is σ = 866096. Its totient is φ = 433044.

The previous prime is 649567. The next prime is 649573. The reversal of 649569 is 965946.

649569 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 649569 - 2¹ = 649567 is a prime.

It is a super-2 number, since 2×649569² = 843879771522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108259 + ... + 108264.

It is an arithmetic number, because the mean of its divisors is an integer number (216524).

2⁶⁴⁹⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

649569 is a deficient number, since it is larger than the sum of its proper divisors (216527).

649569 is a wasteful number, since it uses less digits than its factorization.

649569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216526.

The product of its digits is 58320, while the sum is 39.

The square root of 649569 is about 805.9584356529. The cubic root of 649569 is about 86.6047601954.

The spelling of 649569 in words is "six hundred forty-nine thousand, five hundred sixty-nine".