345220621 has 2 divisors, whose sum is σ = 345220622. Its totient is φ = 345220620.

The previous prime is 345220609. The next prime is 345220637. The reversal of 345220621 is 126022543.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208658025 + 136562596 = 14445^2 + 11686^2 .

It is a cyclic number.

It is not a de Polignac number, because 345220621 - 2⁷ = 345220493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345220651) 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, 172610310 + 172610311.

It is an arithmetic number, because the mean of its divisors is an integer number (172610311).

Almost surely, 2^345220621 is an apocalyptic number.

It is an amenable number.

345220621 is a deficient number, since it is larger than the sum of its proper divisors (1).

345220621 is an equidigital number, since it uses as much as digits as its factorization.

345220621 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 345220621 is about 18580.1135895344. The cubic root of 345220621 is about 701.5073782162.

The spelling of 345220621 in words is "three hundred forty-five million, two hundred twenty thousand, six hundred twenty-one".