345620221 has 2 divisors, whose sum is σ = 345620222. Its totient is φ = 345620220.

The previous prime is 345620207. The next prime is 345620227. The reversal of 345620221 is 122026543.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201356100 + 144264121 = 14190^2 + 12011^2 .

It is a cyclic number.

It is not a de Polignac number, because 345620221 - 2⁵ = 345620189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345620227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172810110 + 172810111.

It is an arithmetic number, because the mean of its divisors is an integer number (172810111).

Almost surely, 2^345620221 is an apocalyptic number.

It is an amenable number.

345620221 is a deficient number, since it is larger than the sum of its proper divisors (1).

345620221 is an equidigital number, since it uses as much as digits as its factorization.

345620221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 345620221 is about 18590.8639121478. The cubic root of 345620221 is about 701.7779436085. Note that the first 3 decimals are identical.

Adding to 345620221 its reverse (122026543), we get a palindrome (467646764).

The spelling of 345620221 in words is "three hundred forty-five million, six hundred twenty thousand, two hundred twenty-one".