345279821 has 2 divisors, whose sum is σ = 345279822. Its totient is φ = 345279820.

The previous prime is 345279817. The next prime is 345279881. The reversal of 345279821 is 128972543.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 302377321 + 42902500 = 17389^2 + 6550^2 .

It is a cyclic number.

It is not a de Polignac number, because 345279821 - 2² = 345279817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345279881) 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, 172639910 + 172639911.

It is an arithmetic number, because the mean of its divisors is an integer number (172639911).

Almost surely, 2^345279821 is an apocalyptic number.

It is an amenable number.

345279821 is a deficient number, since it is larger than the sum of its proper divisors (1).

345279821 is an equidigital number, since it uses as much as digits as its factorization.

345279821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 41.

The square root of 345279821 is about 18581.7066223746. The cubic root of 345279821 is about 701.5474751481.

The spelling of 345279821 in words is "three hundred forty-five million, two hundred seventy-nine thousand, eight hundred twenty-one".