728703421 has 2 divisors, whose sum is σ = 728703422. Its totient is φ = 728703420.

The previous prime is 728703407. The next prime is 728703461. The reversal of 728703421 is 124307827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 663320025 + 65383396 = 25755^2 + 8086^2 .

It is a cyclic number.

It is not a de Polignac number, because 728703421 - 2⁵ = 728703389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728703461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364351710 + 364351711.

It is an arithmetic number, because the mean of its divisors is an integer number (364351711).

Almost surely, 2^728703421 is an apocalyptic number.

It is an amenable number.

728703421 is a deficient number, since it is larger than the sum of its proper divisors (1).

728703421 is an equidigital number, since it uses as much as digits as its factorization.

728703421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 728703421 is about 26994.5072375845. The cubic root of 728703421 is about 899.8779344740.

The spelling of 728703421 in words is "seven hundred twenty-eight million, seven hundred three thousand, four hundred twenty-one".