28311121 has 4 divisors (see below), whose sum is σ = 29801200. Its totient is φ = 26821044.

The previous prime is 28311119. The next prime is 28311149. The reversal of 28311121 is 12111382.

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.

It is a cyclic number.

It is not a de Polignac number, because 28311121 - 2¹ = 28311119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1490059 = 28311121 / (2 + 8 + 3 + 1 + 1 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28311181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 745011 + ... + 745048.

It is an arithmetic number, because the mean of its divisors is an integer number (7450300).

Almost surely, 2^28311121 is an apocalyptic number.

It is an amenable number.

28311121 is a deficient number, since it is larger than the sum of its proper divisors (1490079).

28311121 is a wasteful number, since it uses less digits than its factorization.

28311121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490078.

The product of its digits is 96, while the sum is 19.

The square root of 28311121 is about 5320.8195797264. The cubic root of 28311121 is about 304.7794553621.

The spelling of 28311121 in words is "twenty-eight million, three hundred eleven thousand, one hundred twenty-one".