728708460721 has 2 divisors, whose sum is σ = 728708460722. Its totient is φ = 728708460720.

The previous prime is 728708460653. The next prime is 728708460743. The reversal of 728708460721 is 127064807827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 432554820721 + 296153640000 = 657689^2 + 544200^2 .

It is an emirp because it is prime and its reverse (127064807827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 728708460721 - 2¹³ = 728708452529 is a prime.

It is not a weakly prime, because it can be changed into another prime (728708460751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364354230360 + 364354230361.

It is an arithmetic number, because the mean of its divisors is an integer number (364354230361).

Almost surely, 2^728708460721 is an apocalyptic number.

It is an amenable number.

728708460721 is a deficient number, since it is larger than the sum of its proper divisors (1).

728708460721 is an equidigital number, since it uses as much as digits as its factorization.

728708460721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2107392, while the sum is 52.

The spelling of 728708460721 in words is "seven hundred twenty-eight billion, seven hundred eight million, four hundred sixty thousand, seven hundred twenty-one".