649321 has 2 divisors, whose sum is σ = 649322. Its totient is φ = 649320.

The previous prime is 649307. The next prime is 649361. The reversal of 649321 is 123946.

649321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 1296 = 805^2 + 36^2 .

It is a cyclic number.

It is not a de Polignac number, because 649321 - 2¹³ = 641129 is a prime.

It is a super-2 number, since 2×649321² = 843235522082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (649361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324660 + 324661.

It is an arithmetic number, because the mean of its divisors is an integer number (324661).

2⁶⁴⁹³²¹ is an apocalyptic number.

It is an amenable number.

649321 is a deficient number, since it is larger than the sum of its proper divisors (1).

649321 is an equidigital number, since it uses as much as digits as its factorization.

649321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 25.

The square root of 649321 is about 805.8045668771. The cubic root of 649321 is about 86.5937371352.

Subtracting from 649321 its product of digits (1296), we obtain a square (648025 = 805²).

The spelling of 649321 in words is "six hundred forty-nine thousand, three hundred twenty-one".