28039811 has 4 divisors (see below), whose sum is σ = 28423992. Its totient is φ = 27655632.

The previous prime is 28039799. The next prime is 28039819. The reversal of 28039811 is 11893082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11893082 = 2 ⋅5946541.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28039811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28039819) 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, 191981 + ... + 192126.

It is an arithmetic number, because the mean of its divisors is an integer number (7105998).

Almost surely, 2^28039811 is an apocalyptic number.

28039811 is a deficient number, since it is larger than the sum of its proper divisors (384181).

28039811 is an equidigital number, since it uses as much as digits as its factorization.

28039811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384180.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 28039811 is about 5295.2630718407. The cubic root of 28039811 is about 303.8027452760.

The spelling of 28039811 in words is "twenty-eight million, thirty-nine thousand, eight hundred eleven".