728723405 has 4 divisors (see below), whose sum is σ = 874468092. Its totient is φ = 582978720.

The previous prime is 728723353. The next prime is 728723419. The reversal of 728723405 is 504327827.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 476898244 + 251825161 = 21838^2 + 15869^2 .

It is not a de Polignac number, because 728723405 - 2¹⁶ = 728657869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72872336 + ... + 72872345.

It is an arithmetic number, because the mean of its divisors is an integer number (218617023).

Almost surely, 2^728723405 is an apocalyptic number.

It is an amenable number.

728723405 is a deficient number, since it is larger than the sum of its proper divisors (145744687).

728723405 is a wasteful number, since it uses less digits than its factorization.

728723405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145744686.

The product of its (nonzero) digits is 94080, while the sum is 38.

The square root of 728723405 is about 26994.8773844224. The cubic root of 728723405 is about 899.8861604984.

The spelling of 728723405 in words is "seven hundred twenty-eight million, seven hundred twenty-three thousand, four hundred five".