345278809 has 2 divisors, whose sum is σ = 345278810. Its totient is φ = 345278808.

The previous prime is 345278723. The next prime is 345278833. The reversal of 345278809 is 908872543.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 332697600 + 12581209 = 18240^2 + 3547^2 .

It is a cyclic number.

It is not a de Polignac number, because 345278809 - 2¹³ = 345270617 is a prime.

It is not a weakly prime, because it can be changed into another prime (345278839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172639404 + 172639405.

It is an arithmetic number, because the mean of its divisors is an integer number (172639405).

Almost surely, 2^345278809 is an apocalyptic number.

It is an amenable number.

345278809 is a deficient number, since it is larger than the sum of its proper divisors (1).

345278809 is an equidigital number, since it uses as much as digits as its factorization.

345278809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 483840, while the sum is 46.

The square root of 345278809 is about 18581.6793912714. The cubic root of 345278809 is about 701.5467897458.

The spelling of 345278809 in words is "three hundred forty-five million, two hundred seventy-eight thousand, eight hundred nine".