345642809 has 4 divisors (see below), whose sum is σ = 350377716. Its totient is φ = 340907904.

The previous prime is 345642797. The next prime is 345642853. The reversal of 345642809 is 908246543.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 208167184 + 137475625 = 14428^2 + 11725^2 .

It is a cyclic number.

It is not a de Polignac number, because 345642809 - 2⁸ = 345642553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (345642109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2367344 + ... + 2367489.

It is an arithmetic number, because the mean of its divisors is an integer number (87594429).

Almost surely, 2^345642809 is an apocalyptic number.

It is an amenable number.

345642809 is a deficient number, since it is larger than the sum of its proper divisors (4734907).

345642809 is an equidigital number, since it uses as much as digits as its factorization.

345642809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4734906.

The product of its (nonzero) digits is 207360, while the sum is 41.

The square root of 345642809 is about 18591.4714049211. The cubic root of 345642809 is about 701.7932315015.

It can be divided in two parts, 34564 and 2809, that added together give a palindrome (37373).

The spelling of 345642809 in words is "three hundred forty-five million, six hundred forty-two thousand, eight hundred nine".