321720130 has 16 divisors (see below), whose sum is σ = 580928760. Its totient is φ = 128280832.

The previous prime is 321720127. The next prime is 321720169. The reversal of 321720130 is 31027123.

It can be written as a sum of positive squares in 4 ways, for example, as 207849889 + 113870241 = 14417^2 + 10671^2 .

It is a junction number, because it is equal to n+sod(n) for n = 321720098 and 321720107.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 47575 + ... + 53914.

Almost surely, 2^321720130 is an apocalyptic number.

321720130 is a deficient number, since it is larger than the sum of its proper divisors (259208630).

321720130 is a wasteful number, since it uses less digits than its factorization.

321720130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101813.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 321720130 is about 17936.5584770323. The cubic root of 321720130 is about 685.2137646022.

Adding to 321720130 its reverse (31027123), we get a palindrome (352747253).

The spelling of 321720130 in words is "three hundred twenty-one million, seven hundred twenty thousand, one hundred thirty".