321212345 has 4 divisors (see below), whose sum is σ = 385454820. Its totient is φ = 256969872.

The previous prime is 321212329. The next prime is 321212357. The reversal of 321212345 is 543212123.

321212345 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 247527289 + 73685056 = 15733^2 + 8584^2 .

It is a cyclic number.

It is not a de Polignac number, because 321212345 - 2⁴ = 321212329 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 321212345.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32121230 + ... + 32121239.

It is an arithmetic number, because the mean of its divisors is an integer number (96363705).

Almost surely, 2^321212345 is an apocalyptic number.

It is an amenable number.

321212345 is a deficient number, since it is larger than the sum of its proper divisors (64242475).

321212345 is an equidigital number, since it uses as much as digits as its factorization.

321212345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64242474.

The product of its digits is 1440, while the sum is 23.

The square root of 321212345 is about 17922.3978585456. The cubic root of 321212345 is about 684.8530737857.

Adding to 321212345 its reverse (543212123), we get a palindrome (864424468).

The spelling of 321212345 in words is "three hundred twenty-one million, two hundred twelve thousand, three hundred forty-five".