728170311509 has 2 divisors, whose sum is σ = 728170311510. Its totient is φ = 728170311508.

The previous prime is 728170311499. The next prime is 728170311569. The reversal of 728170311509 is 905113071827.

728170311509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 453059571409 + 275110740100 = 673097^2 + 524510^2 .

It is a cyclic number.

It is not a de Polignac number, because 728170311509 - 2¹² = 728170307413 is a prime.

It is a super-2 number, since 2×728170311509² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 728170311509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728170311569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364085155754 + 364085155755.

It is an arithmetic number, because the mean of its divisors is an integer number (364085155755).

Almost surely, 2^728170311509 is an apocalyptic number.

It is an amenable number.

728170311509 is a deficient number, since it is larger than the sum of its proper divisors (1).

728170311509 is an equidigital number, since it uses as much as digits as its factorization.

728170311509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 105840, while the sum is 44.

The spelling of 728170311509 in words is "seven hundred twenty-eight billion, one hundred seventy million, three hundred eleven thousand, five hundred nine".