728663401421 has 2 divisors, whose sum is σ = 728663401422. Its totient is φ = 728663401420.

The previous prime is 728663401409. The next prime is 728663401483. The reversal of 728663401421 is 124104366827.

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., 680641500100 + 48021901321 = 825010^2 + 219139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-728663401421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728663403421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364331700710 + 364331700711.

It is an arithmetic number, because the mean of its divisors is an integer number (364331700711).

Almost surely, 2^728663401421 is an apocalyptic number.

It is an amenable number.

728663401421 is a deficient number, since it is larger than the sum of its proper divisors (1).

728663401421 is an equidigital number, since it uses as much as digits as its factorization.

728663401421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 44.

The spelling of 728663401421 in words is "seven hundred twenty-eight billion, six hundred sixty-three million, four hundred one thousand, four hundred twenty-one".