28311889 has 4 divisors (see below), whose sum is σ = 28710720. Its totient is φ = 27913060.

The previous prime is 28311887. The next prime is 28311901. The reversal of 28311889 is 98811382.

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: 98811382 = 2 ⋅49405691.

It is a cyclic number.

It is not a de Polignac number, because 28311889 - 2¹ = 28311887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28311883) 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, 199309 + ... + 199450.

It is an arithmetic number, because the mean of its divisors is an integer number (7177680).

Almost surely, 2^28311889 is an apocalyptic number.

It is an amenable number.

28311889 is a deficient number, since it is larger than the sum of its proper divisors (398831).

28311889 is an equidigital number, since it uses as much as digits as its factorization.

28311889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398830.

The product of its digits is 27648, while the sum is 40.

The square root of 28311889 is about 5320.8917485700. The cubic root of 28311889 is about 304.7822112698.

The spelling of 28311889 in words is "twenty-eight million, three hundred eleven thousand, eight hundred eighty-nine".