28753921 has 16 divisors (see below), whose sum is σ = 34274176. Its totient is φ = 23607936.

The previous prime is 28753909. The next prime is 28753937. The reversal of 28753921 is 12935782.

It is a cyclic number.

It is not a de Polignac number, because 28753921 - 2¹¹ = 28751873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28753961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16525 + ... + 18181.

It is an arithmetic number, because the mean of its divisors is an integer number (2142136).

It is a Proth number, since it is equal to 1755 ⋅ 2¹⁴ + 1 and 1755 < 2¹⁴.

Almost surely, 2^28753921 is an apocalyptic number.

It is an amenable number.

28753921 is a deficient number, since it is larger than the sum of its proper divisors (5520255).

28753921 is a wasteful number, since it uses less digits than its factorization.

28753921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768.

The product of its digits is 30240, while the sum is 37.

The square root of 28753921 is about 5362.2682700514. The cubic root of 28753921 is about 306.3602098968.

The spelling of 28753921 in words is "twenty-eight million, seven hundred fifty-three thousand, nine hundred twenty-one".