649421 has 2 divisors, whose sum is σ = 649422. Its totient is φ = 649420.

The previous prime is 649403. The next prime is 649423. The reversal of 649421 is 124946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 346921 + 302500 = 589^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 649421 - 2¹⁴ = 633037 is a prime.

Together with 649423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649423) 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 as a sum of consecutive naturals, namely, 324710 + 324711.

It is an arithmetic number, because the mean of its divisors is an integer number (324711).

2⁶⁴⁹⁴²¹ is an apocalyptic number.

It is an amenable number.

649421 is a deficient number, since it is larger than the sum of its proper divisors (1).

649421 is an equidigital number, since it uses as much as digits as its factorization.

649421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 649421 is about 805.8666142731. The cubic root of 649421 is about 86.5981822552.

The spelling of 649421 in words is "six hundred forty-nine thousand, four hundred twenty-one".