817505434321 has 2 divisors, whose sum is σ = 817505434322. Its totient is φ = 817505434320.

The previous prime is 817505434301. The next prime is 817505434363. The reversal of 817505434321 is 123434505718.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 781570924225 + 35934510096 = 884065^2 + 189564^2 .

It is a cyclic number.

It is not a de Polignac number, because 817505434321 - 2¹⁷ = 817505303249 is a prime.

It is not a weakly prime, because it can be changed into another prime (817505434301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408752717160 + 408752717161.

It is an arithmetic number, because the mean of its divisors is an integer number (408752717161).

Almost surely, 2^817505434321 is an apocalyptic number.

It is an amenable number.

817505434321 is a deficient number, since it is larger than the sum of its proper divisors (1).

817505434321 is an equidigital number, since it uses as much as digits as its factorization.

817505434321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 403200, while the sum is 43.

The spelling of 817505434321 in words is "eight hundred seventeen billion, five hundred five million, four hundred thirty-four thousand, three hundred twenty-one".