321728937734416 has 15 divisors (see below), whose sum is σ = 623349955870693. Its totient is φ = 160864432993600.

The previous prime is 321728937734387. The next prime is 321728937734417. The reversal of 321728937734416 is 614437739827123.

It is a happy number.

The square root of 321728937734416 is 17936804.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 299622390636816 + 22106547097600 = 17309604^2 + 4701760^2 .

It is a super-2 number, since 2×321728937734416² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321728937734417) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 69505116 + ... + 73989316.

Almost surely, 2^{321728937734416} is an apocalyptic number.

321728937734416 is the 17936804-th square number.

It is an amenable number.

321728937734416 is a deficient number, since it is larger than the sum of its proper divisors (301621018136277).

321728937734416 is an frugal number, since it uses more digits than its factorization.

321728937734416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8968410 (or 4484203 counting only the distinct ones).

The product of its digits is 256048128, while the sum is 67.

The spelling of 321728937734416 in words is "three hundred twenty-one trillion, seven hundred twenty-eight billion, nine hundred thirty-seven million, seven hundred thirty-four thousand, four hundred sixteen".