728003637121 has 2 divisors, whose sum is σ = 728003637122. Its totient is φ = 728003637120.

The previous prime is 728003637113. The next prime is 728003637133. The reversal of 728003637121 is 121736300827.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 427145902096 + 300857735025 = 653564^2 + 548505^2 .

It is a cyclic number.

It is not a de Polignac number, because 728003637121 - 2³ = 728003637113 is a prime.

It is a super-2 number, since 2×728003637121² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (728003637191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364001818560 + 364001818561.

It is an arithmetic number, because the mean of its divisors is an integer number (364001818561).

Almost surely, 2^728003637121 is an apocalyptic number.

It is an amenable number.

728003637121 is a deficient number, since it is larger than the sum of its proper divisors (1).

728003637121 is an equidigital number, since it uses as much as digits as its factorization.

728003637121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 40.

Adding to 728003637121 its reverse (121736300827), we get a palindrome (849739937948).

The spelling of 728003637121 in words is "seven hundred twenty-eight billion, three million, six hundred thirty-seven thousand, one hundred twenty-one".