649947 has 4 divisors (see below), whose sum is σ = 866600. Its totient is φ = 433296.

The previous prime is 649937. The next prime is 649969. The reversal of 649947 is 749946.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 649947 - 2¹² = 645851 is a prime.

It is a super-2 number, since 2×649947² = 844862205618, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649907) 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 3 ways as a sum of consecutive naturals, for example, 108322 + ... + 108327.

It is an arithmetic number, because the mean of its divisors is an integer number (216650).

2⁶⁴⁹⁹⁴⁷ is an apocalyptic number.

649947 is a deficient number, since it is larger than the sum of its proper divisors (216653).

649947 is a wasteful number, since it uses less digits than its factorization.

649947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216652.

The product of its digits is 54432, while the sum is 39.

The square root of 649947 is about 806.1929049551. The cubic root of 649947 is about 86.6215560766.

Subtracting 649947 from its reverse (749946), we obtain a palindrome (99999).

It can be divided in two parts, 649 and 947, that added together give a triangular number (1596 = T₅₆).

The spelling of 649947 in words is "six hundred forty-nine thousand, nine hundred forty-seven".