345521321 has 2 divisors, whose sum is σ = 345521322. Its totient is φ = 345521320.

The previous prime is 345521291. The next prime is 345521333. The reversal of 345521321 is 123125543.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 308494096 + 37027225 = 17564^2 + 6085^2 .

It is a cyclic number.

It is not a de Polignac number, because 345521321 - 2¹⁸ = 345259177 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (345521221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172760660 + 172760661.

It is an arithmetic number, because the mean of its divisors is an integer number (172760661).

Almost surely, 2^345521321 is an apocalyptic number.

It is an amenable number.

345521321 is a deficient number, since it is larger than the sum of its proper divisors (1).

345521321 is an equidigital number, since it uses as much as digits as its factorization.

345521321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 26.

The square root of 345521321 is about 18588.2038131714. The cubic root of 345521321 is about 701.7109987794.

Adding to 345521321 its reverse (123125543), we get a palindrome (468646864).

The spelling of 345521321 in words is "three hundred forty-five million, five hundred twenty-one thousand, three hundred twenty-one".