9028721 has 8 divisors (see below), whose sum is σ = 9765504. Its totient is φ = 8298000.

The previous prime is 9028699. The next prime is 9028741. The reversal of 9028721 is 1278209.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9028721 - 2¹⁴ = 9012337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9028741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1880 + ... + 4646.

It is an arithmetic number, because the mean of its divisors is an integer number (1220688).

Almost surely, 2^9028721 is an apocalyptic number.

It is an amenable number.

9028721 is a deficient number, since it is larger than the sum of its proper divisors (736783).

9028721 is a wasteful number, since it uses less digits than its factorization.

9028721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3031.

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

The square root of 9028721 is about 3004.7830204526. The cubic root of 9028721 is about 208.2294143416.

The spelling of 9028721 in words is "nine million, twenty-eight thousand, seven hundred twenty-one".