728721515 has 16 divisors (see below), whose sum is σ = 880056576. Its totient is φ = 579264000.

The previous prime is 728721509. The next prime is 728721533. The reversal of 728721515 is 515127827.

It is not a de Polignac number, because 728721515 - 2⁶ = 728721451 is a prime.

It is a Duffinian number.

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, 843974 + ... + 844836.

It is an arithmetic number, because the mean of its divisors is an integer number (55003536).

Almost surely, 2^728721515 is an apocalyptic number.

728721515 is a deficient number, since it is larger than the sum of its proper divisors (151335061).

728721515 is a wasteful number, since it uses less digits than its factorization.

728721515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1750.

The product of its digits is 39200, while the sum is 38.

The square root of 728721515 is about 26994.8423777580. The cubic root of 728721515 is about 899.8853825231.

The spelling of 728721515 in words is "seven hundred twenty-eight million, seven hundred twenty-one thousand, five hundred fifteen".