649923 has 4 divisors (see below), whose sum is σ = 866568. Its totient is φ = 433280.

The previous prime is 649921. The next prime is 649937. The reversal of 649923 is 329946.

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

It is a cyclic number.

It is not a de Polignac number, because 649923 - 2¹ = 649921 is a prime.

It is a D-number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (649921) 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 3 ways as a sum of consecutive naturals, for example, 108318 + ... + 108323.

It is an arithmetic number, because the mean of its divisors is an integer number (216642).

2⁶⁴⁹⁹²³ is an apocalyptic number.

649923 is a deficient number, since it is larger than the sum of its proper divisors (216645).

649923 is a wasteful number, since it uses less digits than its factorization.

649923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216644.

The product of its digits is 11664, while the sum is 33.

The square root of 649923 is about 806.1780200427. The cubic root of 649923 is about 86.6204898651.

The spelling of 649923 in words is "six hundred forty-nine thousand, nine hundred twenty-three".