28728911 has 2 divisors, whose sum is σ = 28728912. Its totient is φ = 28728910.

The previous prime is 28728881. The next prime is 28728919. The reversal of 28728911 is 11982782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28728911 - 2¹⁰ = 28727887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28728919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14364455 + 14364456.

It is an arithmetic number, because the mean of its divisors is an integer number (14364456).

Almost surely, 2^28728911 is an apocalyptic number.

28728911 is a deficient number, since it is larger than the sum of its proper divisors (1).

28728911 is an equidigital number, since it uses as much as digits as its factorization.

28728911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 38.

The square root of 28728911 is about 5359.9357272266. The cubic root of 28728911 is about 306.2713606647.

The spelling of 28728911 in words is "twenty-eight million, seven hundred twenty-eight thousand, nine hundred eleven".