649997 has 4 divisors (see below), whose sum is σ = 656796. Its totient is φ = 643200.

The previous prime is 649991. The next prime is 650011. The reversal of 649997 is 799946.

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

It can be written as a sum of positive squares in 2 ways, for example, as 276676 + 373321 = 526^2 + 611^2 .

It is a cyclic number.

It is not a de Polignac number, because 649997 - 2⁴ = 649981 is a prime.

It is a super-2 number, since 2×649997² = 844992200018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649991) 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, 3254 + ... + 3447.

It is an arithmetic number, because the mean of its divisors is an integer number (164199).

2⁶⁴⁹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

649997 is a deficient number, since it is larger than the sum of its proper divisors (6799).

649997 is an equidigital number, since it uses as much as digits as its factorization.

649997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6798.

The product of its digits is 122472, while the sum is 44.

The square root of 649997 is about 806.2239143067. The cubic root of 649997 is about 86.6237772663.

The spelling of 649997 in words is "six hundred forty-nine thousand, nine hundred ninety-seven".