928721 has 4 divisors (see below), whose sum is σ = 930672. Its totient is φ = 926772.

The previous prime is 928703. The next prime is 928769. The reversal of 928721 is 127829.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127829 = 13 ⋅9833.

It is a cyclic number.

It is not a de Polignac number, because 928721 - 2¹⁴ = 912337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (928771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266 + ... + 1388.

It is an arithmetic number, because the mean of its divisors is an integer number (232668).

2⁹²⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

928721 is a deficient number, since it is larger than the sum of its proper divisors (1951).

928721 is a wasteful number, since it uses less digits than its factorization.

928721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1950.

The product of its digits is 2016, while the sum is 29.

The square root of 928721 is about 963.7017173379. The cubic root of 928721 is about 97.5652335748.

The spelling of 928721 in words is "nine hundred twenty-eight thousand, seven hundred twenty-one".