616321 has 2 divisors, whose sum is σ = 616322. Its totient is φ = 616320.

The previous prime is 616313. The next prime is 616327. The reversal of 616321 is 123616.

It is the 321-st star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 608400 + 7921 = 780^2 + 89^2 .

It is a cyclic number.

It is not a de Polignac number, because 616321 - 2³ = 616313 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

616321 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (616327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308160 + 308161.

It is an arithmetic number, because the mean of its divisors is an integer number (308161).

2⁶¹⁶³²¹ is an apocalyptic number.

It is an amenable number.

616321 is a deficient number, since it is larger than the sum of its proper divisors (1).

616321 is an equidigital number, since it uses as much as digits as its factorization.

616321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 19.

The square root of 616321 is about 785.0611441155. The cubic root of 616321 is about 85.1011943570.

Adding to 616321 its reverse (123616), we get a palindrome (739937).

The spelling of 616321 in words is "six hundred sixteen thousand, three hundred twenty-one".