28312161 has 4 divisors (see below), whose sum is σ = 37749552. Its totient is φ = 18874772.

The previous prime is 28312159. The next prime is 28312177. The reversal of 28312161 is 16121382.

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 28312161 - 2¹ = 28312159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28312561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4718691 + ... + 4718696.

It is an arithmetic number, because the mean of its divisors is an integer number (9437388).

Almost surely, 2^28312161 is an apocalyptic number.

It is an amenable number.

28312161 is a deficient number, since it is larger than the sum of its proper divisors (9437391).

28312161 is an equidigital number, since it uses as much as digits as its factorization.

28312161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9437390.

The product of its digits is 576, while the sum is 24.

The square root of 28312161 is about 5320.9173081340. The cubic root of 28312161 is about 304.7831873085.

The spelling of 28312161 in words is "twenty-eight million, three hundred twelve thousand, one hundred sixty-one".