28911563 has 4 divisors (see below), whose sum is σ = 29014008. Its totient is φ = 28809120.

The previous prime is 28911557. The next prime is 28911599. The reversal of 28911563 is 36511982.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28911563 - 2¹⁴ = 28895179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28911263) 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, 50798 + ... + 51363.

It is an arithmetic number, because the mean of its divisors is an integer number (7253502).

Almost surely, 2^28911563 is an apocalyptic number.

28911563 is a deficient number, since it is larger than the sum of its proper divisors (102445).

28911563 is a wasteful number, since it uses less digits than its factorization.

28911563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102444.

The product of its digits is 12960, while the sum is 35.

The square root of 28911563 is about 5376.9473681635. The cubic root of 28911563 is about 306.9190582625.

The spelling of 28911563 in words is "twenty-eight million, nine hundred eleven thousand, five hundred sixty-three".