728720905 has 16 divisors (see below), whose sum is σ = 961253568. Its totient is φ = 525928000.

The previous prime is 728720899. The next prime is 728720911. The reversal of 728720905 is 509027827.

It is an interprime number because it is at equal distance from previous prime (728720899) and next prime (728720911).

It is not a de Polignac number, because 728720905 - 2⁵ = 728720873 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43366 + ... + 57775.

It is an arithmetic number, because the mean of its divisors is an integer number (60078348).

Almost surely, 2^728720905 is an apocalyptic number.

It is an amenable number.

728720905 is a deficient number, since it is larger than the sum of its proper divisors (232532663).

728720905 is a wasteful number, since it uses less digits than its factorization.

728720905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101288.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 728720905 is about 26994.8310793011. The cubic root of 728720905 is about 899.8851314303.

The spelling of 728720905 in words is "seven hundred twenty-eight million, seven hundred twenty thousand, nine hundred five".