728478843581 has 2 divisors, whose sum is σ = 728478843582. Its totient is φ = 728478843580.

The previous prime is 728478843563. The next prime is 728478843583. The reversal of 728478843581 is 185348874827.

728478843581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 713670144100 + 14808699481 = 844790^2 + 121691^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-728478843581 is a prime.

It is a super-2 number, since 2×728478843581² (a number of 25 digits) contains 22 as substring.

Together with 728478843583, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728478843583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364239421790 + 364239421791.

It is an arithmetic number, because the mean of its divisors is an integer number (364239421791).

Almost surely, 2^728478843581 is an apocalyptic number.

It is an amenable number.

728478843581 is a deficient number, since it is larger than the sum of its proper divisors (1).

728478843581 is an equidigital number, since it uses as much as digits as its factorization.

728478843581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96337920, while the sum is 65.

The spelling of 728478843581 in words is "seven hundred twenty-eight billion, four hundred seventy-eight million, eight hundred forty-three thousand, five hundred eighty-one".