321630345 has 20 divisors (see below), whose sum is σ = 576552900. Its totient is φ = 171535968.

The previous prime is 321630343. The next prime is 321630371. The reversal of 321630345 is 543036123.

It is a happy number.

321630345 is a `hidden beast` number, since 3 + 21 + 630 + 3 + 4 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 193849929 + 127780416 = 13923^2 + 11304^2 .

It is not a de Polignac number, because 321630345 - 2¹ = 321630343 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (321630343) 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 in 19 ways as a sum of consecutive naturals, for example, 396670 + ... + 397479.

It is an arithmetic number, because the mean of its divisors is an integer number (28827645).

Almost surely, 2^321630345 is an apocalyptic number.

It is an amenable number.

321630345 is a deficient number, since it is larger than the sum of its proper divisors (254922555).

321630345 is an equidigital number, since it uses as much as digits as its factorization.

321630345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794166 (or 794157 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 27.

The square root of 321630345 is about 17934.0554532431. The cubic root of 321630345 is about 685.1500159833.

Adding to 321630345 its reverse (543036123), we get a palindrome (864666468).

The spelling of 321630345 in words is "three hundred twenty-one million, six hundred thirty thousand, three hundred forty-five".