345645221 has 2 divisors, whose sum is σ = 345645222. Its totient is φ = 345645220.

The previous prime is 345645199. The next prime is 345645227. The reversal of 345645221 is 122546543.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 345588100 + 57121 = 18590^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 345645221 - 2¹⁴ = 345628837 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345645227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172822610 + 172822611.

It is an arithmetic number, because the mean of its divisors is an integer number (172822611).

Almost surely, 2^345645221 is an apocalyptic number.

It is an amenable number.

345645221 is a deficient number, since it is larger than the sum of its proper divisors (1).

345645221 is an equidigital number, since it uses as much as digits as its factorization.

345645221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 32.

The square root of 345645221 is about 18591.5362732616. The cubic root of 345645221 is about 701.7948639395.

The spelling of 345645221 in words is "three hundred forty-five million, six hundred forty-five thousand, two hundred twenty-one".