321720460 has 12 divisors (see below), whose sum is σ = 675613008. Its totient is φ = 128688176.

The previous prime is 321720433. The next prime is 321720467. The reversal of 321720460 is 64027123.

It is a super-2 number, since 2×321720460² = 207008108765223200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (321720467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8042992 + ... + 8043031.

It is an arithmetic number, because the mean of its divisors is an integer number (56301084).

Almost surely, 2^321720460 is an apocalyptic number.

It is an amenable number.

321720460 is an abundant number, since it is smaller than the sum of its proper divisors (353892548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

321720460 is a wasteful number, since it uses less digits than its factorization.

321720460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16086032 (or 16086030 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 321720460 is about 17936.5676761191. The cubic root of 321720460 is about 685.2139988850.

Adding to 321720460 its reverse (64027123), we get a palindrome (385747583).

The spelling of 321720460 in words is "three hundred twenty-one million, seven hundred twenty thousand, four hundred sixty".